diff --git a/robotframework-ls/src/robotframework_ls/impl/code_analysis.py b/robotframework-ls/src/robotframework_ls/impl/code_analysis.py
index 93a3b73b6a..336ac94af6 100644
--- a/robotframework-ls/src/robotframework_ls/impl/code_analysis.py
+++ b/robotframework-ls/src/robotframework_ls/impl/code_analysis.py
@@ -1,7 +1,10 @@
+from typing import Dict, Set
+
+from robocorp_ls_core.protocols import check_implements
 from robocorp_ls_core.robotframework_log import get_logger
 from robotframework_ls.impl.ast_utils import MAX_ERRORS
-from typing import Dict, Set
-from robotframework_ls.impl.protocols import IKeywordFound
+from robotframework_ls.impl.protocols import IKeywordFound, IKeywordCollector
+
 
 log = get_logger(__name__)
 
@@ -35,11 +38,13 @@ def contains_keyword(self, normalized_keyword_name):
         return False
 
 
-class _KeywordsCollector(object):
-    def __init__(self):
+class _AnalysisKeywordsCollector(object):
+    def __init__(self, on_unresolved_library, on_unresolved_resource):
         self._keywords_container = _KeywordContainer()
         self._resource_name_to_keywords_container = {}
         self._library_name_to_keywords_container = {}
+        self._on_unresolved_library = on_unresolved_library
+        self._on_unresolved_resource = on_unresolved_resource
 
     def accepts(self, keyword_name):
         return True
@@ -108,6 +113,33 @@ def contains_keyword(self, normalized_keyword_name):
 
         return False
 
+    def on_unresolved_library(
+        self,
+        library_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        self._on_unresolved_library(
+            library_name, lineno, end_lineno, col_offset, end_col_offset
+        )
+
+    def on_unresolved_resource(
+        self,
+        resource_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        self._on_unresolved_resource(
+            resource_name, lineno, end_lineno, col_offset, end_col_offset
+        )
+
+    def __typecheckself__(self) -> None:
+        _: IKeywordCollector = check_implements(self)
+
 
 def collect_analysis_errors(completion_context):
     from robotframework_ls.impl import ast_utils
@@ -117,7 +149,36 @@ def collect_analysis_errors(completion_context):
     from robotframework_ls.impl.text_utilities import contains_variable_text
 
     errors = []
-    collector = _KeywordsCollector()
+
+    def on_unresolved_library(
+        library_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        start = (lineno - 1, col_offset)
+        end = (end_lineno - 1, end_col_offset)
+        errors.append(
+            ast_utils.Error(f"Unresolved library: {library_name}", start, end)
+        )
+
+    def on_unresolved_resource(
+        library_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        start = (lineno - 1, col_offset)
+        end = (end_lineno - 1, end_col_offset)
+        errors.append(
+            ast_utils.Error(f"Unresolved resource: {library_name}", start, end)
+        )
+
+    collector = _AnalysisKeywordsCollector(
+        on_unresolved_library, on_unresolved_resource
+    )
     collect_keywords(completion_context, collector)
 
     ast = completion_context.get_ast()
diff --git a/robotframework-ls/src/robotframework_ls/impl/collect_keywords.py b/robotframework-ls/src/robotframework_ls/impl/collect_keywords.py
index d328057582..af208141d2 100644
--- a/robotframework-ls/src/robotframework_ls/impl/collect_keywords.py
+++ b/robotframework-ls/src/robotframework_ls/impl/collect_keywords.py
@@ -250,7 +250,7 @@ def _collect_current_doc_keywords(
     _collect_completions_from_ast(ast, completion_context, collector)
 
 
-_LibInfo = namedtuple("_LibInfo", "name, alias, builtin, args")
+_LibInfo = namedtuple("_LibInfo", "name, alias, builtin, args, node")
 
 
 def _collect_libraries_keywords(
@@ -269,11 +269,12 @@ def _collect_libraries_keywords(
     # Note: using a dict(_LibInfo:bool) where only the keys are meaningful
     # because we want to keep the order and sets aren't ordered.
     library_infos = {}
-    for name, alias, args in (
+    for name, alias, args, node in (
         (
             library.name,
             library.alias,
             ast_utils.get_library_arguments_serialized(library),
+            library,
         )
         for library in libraries
     ):
@@ -283,11 +284,12 @@ def _collect_libraries_keywords(
                 alias,
                 False,
                 args,
+                node,
             )
 
             library_infos[lib_info] = True
 
-    library_infos[_LibInfo(BUILTIN_LIB, None, True, None)] = True
+    library_infos[_LibInfo(BUILTIN_LIB, None, True, None, None)] = True
     libspec_manager = completion_context.workspace.libspec_manager
 
     for library_info in library_infos:
@@ -325,12 +327,55 @@ def _collect_libraries_keywords(
                             library_alias=library_info.alias,
                         )
                     )
+        else:
+            from robot.api import Token
+
+            node = library_info.node
+            node_name_tok = node.get_token(Token.NAME)
+            if node_name_tok is not None:
+                collector.on_unresolved_library(
+                    node.name,
+                    node_name_tok.lineno,
+                    node_name_tok.lineno,
+                    node_name_tok.col_offset,
+                    node_name_tok.end_col_offset,
+                )
+            else:
+                collector.on_unresolved_library(
+                    library_info.name,
+                    node.lineno,
+                    node.end_lineno,
+                    node.col_offset,
+                    node.end_col_offset,
+                )
 
 
 def _collect_resource_imports_keywords(
     completion_context: ICompletionContext, collector: IKeywordCollector
 ):
-    for resource_doc in completion_context.get_resource_imports_as_docs():
+
+    for node, resource_doc in completion_context.get_resource_imports_as_docs():
+        if resource_doc is None:
+            from robot.api import Token
+
+            node_name_tok = node.get_token(Token.NAME)
+            if node_name_tok is not None:
+                collector.on_unresolved_resource(
+                    node.name,
+                    node_name_tok.lineno,
+                    node_name_tok.lineno,
+                    node_name_tok.col_offset,
+                    node_name_tok.end_col_offset,
+                )
+            else:
+                collector.on_unresolved_resource(
+                    node.name,
+                    node.lineno,
+                    node.end_lineno,
+                    node.col_offset,
+                    node.end_col_offset,
+                )
+            continue
         new_ctx = completion_context.create_copy(resource_doc)
         _collect_following_imports(new_ctx, collector)
 
@@ -362,6 +407,29 @@ def on_keyword(self, keyword_found: IKeywordFound):
             self.keyword_name_to_keyword_found[keyword_found.keyword_name] = lst = []
         lst.append(keyword_found)
 
+    def on_unresolved_library(
+        self,
+        library_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        pass
+
+    def on_unresolved_resource(
+        self,
+        resource_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        pass
+
+    def __typecheckself__(self) -> None:
+        _: IKeywordCollector = check_implements(self)
+
 
 def collect_keyword_name_to_keyword_found(
     completion_context: ICompletionContext,
diff --git a/robotframework-ls/src/robotframework_ls/impl/completion_context.py b/robotframework-ls/src/robotframework_ls/impl/completion_context.py
index 7ee93637a9..405da265eb 100644
--- a/robotframework-ls/src/robotframework_ls/impl/completion_context.py
+++ b/robotframework-ls/src/robotframework_ls/impl/completion_context.py
@@ -13,6 +13,8 @@
     ILibraryImportNode,
     KeywordUsageInfo,
     CompletionType,
+    INode,
+    IResourceImportNode,
 )
 import sys
 
@@ -450,15 +452,16 @@ def get_variable_import_as_doc(self, variables_import) -> Optional[IRobotDocumen
         return self.get_resource_import_as_doc(variables_import)
 
     @instance_cache
-    def get_resource_imports_as_docs(self) -> Tuple[IRobotDocument, ...]:
-        ret: List[IRobotDocument] = []
+    def get_resource_imports_as_docs(
+        self,
+    ) -> Tuple[Tuple[IResourceImportNode, Optional[IRobotDocument]], ...]:
+        ret: List[Tuple[IResourceImportNode, Optional[IRobotDocument]]] = []
 
         # Get keywords from resources
         resource_imports = self.get_resource_imports()
         for resource_import in resource_imports:
             resource_doc = self.get_resource_import_as_doc(resource_import)
-            if resource_doc is not None:
-                ret.append(resource_doc)
+            ret.append((resource_import, resource_doc))
 
         return tuple(ret)
 
diff --git a/robotframework-ls/src/robotframework_ls/impl/dictionary_completions.py b/robotframework-ls/src/robotframework_ls/impl/dictionary_completions.py
index ed9769f787..b76e282cb4 100644
--- a/robotframework-ls/src/robotframework_ls/impl/dictionary_completions.py
+++ b/robotframework-ls/src/robotframework_ls/impl/dictionary_completions.py
@@ -109,7 +109,12 @@ def complete(completion_context: ICompletionContext):
     except ValueError:
         return []
     variables = _get_variables(completion_context)
-    for resource_doc in completion_context.get_resource_imports_as_docs():
+    for (
+        _resource_node,
+        resource_doc,
+    ) in completion_context.get_resource_imports_as_docs():
+        if resource_doc is None:
+            continue
         new_ctx = completion_context.create_copy(resource_doc)
         variables += _get_variables(new_ctx)
     dict_name = _get_dict_name(value)
diff --git a/robotframework-ls/src/robotframework_ls/impl/find_definition.py b/robotframework-ls/src/robotframework_ls/impl/find_definition.py
index 2520cab248..d977f88600 100644
--- a/robotframework-ls/src/robotframework_ls/impl/find_definition.py
+++ b/robotframework-ls/src/robotframework_ls/impl/find_definition.py
@@ -4,6 +4,8 @@
     IDefinition,
     TokenInfo,
     IKeywordDefinition,
+    IKeywordCollector,
+    IVariablesCollector,
 )
 from robocorp_ls_core.protocols import check_implements
 from typing import Optional, Sequence
@@ -138,15 +140,7 @@ def __typecheckself__(self) -> None:
         _: IDefinition = check_implements(self)
 
 
-class IDefinitionsCollector(object):
-    def accepts(self, keyword_name):
-        pass
-
-    def on_keyword(self, keyword_found):
-        pass
-
-
-class _FindDefinitionKeywordCollector(IDefinitionsCollector):
+class _FindDefinitionKeywordCollector(object):
     def __init__(self, match_name):
         from robotframework_ls.impl.string_matcher import RobotStringMatcher
         from robotframework_ls.impl.string_matcher import (
@@ -174,8 +168,31 @@ def on_keyword(self, keyword_found):
                 self.matches.append(definition)
                 return
 
+    def on_unresolved_library(
+        self,
+        library_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        pass
 
-class _FindDefinitionVariablesCollector(IDefinitionsCollector):
+    def on_unresolved_resource(
+        self,
+        resource_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        pass
+
+    def __typecheckself__(self) -> None:
+        _: IKeywordCollector = check_implements(self)
+
+
+class _FindDefinitionVariablesCollector(object):
     def __init__(self, sel, token, robot_string_matcher):
         self.matches = []
         self.sel = sel
@@ -189,6 +206,9 @@ def on_variable(self, variable_found):
         definition = _DefinitionFromVariable(variable_found)
         self.matches.append(definition)
 
+    def __typecheckself__(self) -> None:
+        _: IVariablesCollector = check_implements(self)
+
 
 def find_keyword_definition(
     completion_context: ICompletionContext, token_info: TokenInfo
diff --git a/robotframework-ls/src/robotframework_ls/impl/keyword_completions.py b/robotframework-ls/src/robotframework_ls/impl/keyword_completions.py
index ad5e00540f..7675eb1bf7 100644
--- a/robotframework-ls/src/robotframework_ls/impl/keyword_completions.py
+++ b/robotframework-ls/src/robotframework_ls/impl/keyword_completions.py
@@ -1,7 +1,14 @@
-from robocorp_ls_core.robotframework_log import get_logger
-from robotframework_ls.impl.protocols import ICompletionContext, IKeywordFound
 from typing import List
 
+from robocorp_ls_core.protocols import check_implements
+from robocorp_ls_core.robotframework_log import get_logger
+from robotframework_ls.impl.protocols import (
+    ICompletionContext,
+    IKeywordFound,
+    IKeywordCollector,
+)
+
+
 log = get_logger(__name__)
 
 
@@ -111,6 +118,29 @@ def on_keyword(self, keyword_found):
 
         self.completion_items.append(item)
 
+    def on_unresolved_library(
+        self,
+        library_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        pass
+
+    def on_unresolved_resource(
+        self,
+        library_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        pass
+
+    def __typecheckself__(self) -> None:
+        _: IKeywordCollector = check_implements(self)
+
 
 def complete(completion_context: ICompletionContext) -> List[dict]:
     from robotframework_ls.impl.collect_keywords import collect_keywords
diff --git a/robotframework-ls/src/robotframework_ls/impl/protocols.py b/robotframework-ls/src/robotframework_ls/impl/protocols.py
index 168c8ba311..6001dcc5a8 100644
--- a/robotframework-ls/src/robotframework_ls/impl/protocols.py
+++ b/robotframework-ls/src/robotframework_ls/impl/protocols.py
@@ -1,5 +1,14 @@
 import sys
-from typing import TypeVar, Any, Optional, List, Sequence, Tuple, Iterable, Generic
+from typing import (
+    TypeVar,
+    Any,
+    Optional,
+    List,
+    Sequence,
+    Tuple,
+    Iterable,
+    Generic,
+)
 from robocorp_ls_core.protocols import (
     Sentinel,
     IMonitor,
@@ -35,6 +44,24 @@ class INode(Protocol):
 class ILibraryImportNode(INode, Protocol):
     name: str
     alias: Optional[str]
+    lineno: int
+    end_lineno: int
+    col_offset: int
+    end_col_offset: int
+
+    def get_token(self, name: str) -> Any:
+        pass
+
+
+class IResourceImportNode(INode, Protocol):
+    name: str
+    lineno: int
+    end_lineno: int
+    col_offset: int
+    end_col_offset: int
+
+    def get_token(self, name: str) -> Any:
+        pass
 
 
 class NodeInfo(Generic[Y]):
@@ -216,6 +243,26 @@ def on_keyword(self, keyword_found: IKeywordFound):
         :param IKeywordFound keyword_found:
         """
 
+    def on_unresolved_library(
+        self,
+        library_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        pass
+
+    def on_unresolved_resource(
+        self,
+        resource_name: str,
+        lineno: int,
+        end_lineno: int,
+        col_offset: int,
+        end_col_offset: int,
+    ):
+        pass
+
 
 class IDefinition(Protocol):
 
@@ -362,7 +409,9 @@ def get_variable_import_as_doc(self, variables_import) -> Optional[IRobotDocumen
     def get_current_keyword_definition(self) -> Optional[IKeywordDefinition]:
         pass
 
-    def get_resource_imports_as_docs(self) -> Tuple[IRobotDocument, ...]:
+    def get_resource_imports_as_docs(
+        self,
+    ) -> Tuple[Tuple[IResourceImportNode, Optional[IRobotDocument]], ...]:
         pass
 
     def get_variable_imports_as_docs(self) -> Tuple[IRobotDocument, ...]:
@@ -378,3 +427,50 @@ def get_current_keyword_definition_and_usage_info(
         self,
     ) -> Optional[Tuple[IKeywordDefinition, KeywordUsageInfo]]:
         pass
+
+
+class IVariableFound(Protocol):
+    """
+    :ivar variable_name:
+    :ivar variable_value:
+    :ivar completion_context:
+        This may be a new completion context, created when a new document is
+        being analyzed (the variable was created for that completion context).
+    :ivar source:
+        Source where the variable was found.
+    :ivar lineno:
+        Line where it was found (0-based).
+    """
+
+    variable_name: str = ""
+    variable_value: str = ""
+    completion_context: Optional[ICompletionContext] = None
+
+    @property
+    def source(self) -> str:
+        pass
+
+    # Note: line/offsets 0-based.
+    @property
+    def lineno(self) -> int:
+        pass
+
+    @property
+    def end_lineno(self) -> int:
+        pass
+
+    @property
+    def col_offset(self) -> int:
+        pass
+
+    @property
+    def end_col_offset(self) -> int:
+        pass
+
+
+class IVariablesCollector(Protocol):
+    def accepts(self, variable_name: str) -> bool:
+        pass
+
+    def on_variable(self, variable_found: IVariableFound):
+        pass
diff --git a/robotframework-ls/src/robotframework_ls/impl/robot_workspace.py b/robotframework-ls/src/robotframework_ls/impl/robot_workspace.py
index 45d769b779..1033a72c39 100644
--- a/robotframework-ls/src/robotframework_ls/impl/robot_workspace.py
+++ b/robotframework-ls/src/robotframework_ls/impl/robot_workspace.py
@@ -25,8 +25,6 @@
 import weakref
 import threading
 from robocorp_ls_core.lsp import TextDocumentContentChangeEvent, TextDocumentItem
-import os
-from robocorp_ls_core.uris import normalize_drive
 from robocorp_ls_core import uris
 
 log = get_logger(__name__)
@@ -292,13 +290,16 @@ def _on_thread(self) -> None:
                         old_cached = self._cached
                         new_cached = {}
 
+                        test_info_lst: List[ITestInfoFromSymbolsCacheTypedDict]
                         for uri, symbols_cache in self.iter_uri_and_symbols_cache():
                             if symbols_cache is None:
                                 test_info_lst = []
                             else:
-                                test_info_lst = symbols_cache.get_test_info()
-                                if test_info_lst is None:
+                                lst = symbols_cache.get_test_info()
+                                if lst is None:
                                     test_info_lst = []
+                                else:
+                                    test_info_lst = lst
 
                             if uri:
                                 test_info_for_uri: ITestInfoFromUriTypedDict = {
@@ -334,12 +335,14 @@ def _on_thread(self) -> None:
                             if symbols_cache is None:
                                 test_info_lst = []
                             else:
-                                test_info_lst = symbols_cache.get_test_info()
-                                if test_info_lst is None:
+                                lst = symbols_cache.get_test_info()
+                                if lst is None:
                                     test_info_lst = []
+                                else:
+                                    test_info_lst = lst
 
                             if uri:
-                                test_info_for_uri: ITestInfoFromUriTypedDict = {
+                                test_info_for_uri = {
                                     "uri": uri,
                                     "testInfo": test_info_lst,
                                 }
diff --git a/robotframework-ls/src/robotframework_ls/impl/variable_completions.py b/robotframework-ls/src/robotframework_ls/impl/variable_completions.py
index 0e257ad728..0459e8941d 100644
--- a/robotframework-ls/src/robotframework_ls/impl/variable_completions.py
+++ b/robotframework-ls/src/robotframework_ls/impl/variable_completions.py
@@ -1,36 +1,17 @@
 from robocorp_ls_core.cache import instance_cache
-from robotframework_ls.impl.protocols import ICompletionContext, IRobotDocument
+from robotframework_ls.impl.protocols import (
+    ICompletionContext,
+    IRobotDocument,
+    IVariablesCollector,
+    IVariableFound,
+)
 from robocorp_ls_core.robotframework_log import get_logger
-from typing import Any
+from robocorp_ls_core.protocols import check_implements
+from typing import Optional
 
 log = get_logger(__name__)
 
 
-class IVariableFound(object):
-    """
-    :ivar variable_name:
-    :ivar variable_value:
-    :ivar completion_context:
-        This may be a new completion context, created when a new document is
-        being analyzed (the variable was created for that completion context).
-    :ivar source:
-        Source where the variable was found.
-    :ivar lineno:
-        Line where it was found (0-based).
-    """
-
-    variable_name = ""
-    variable_value = ""
-    completion_context = None
-    source = ""
-
-    # Note: line/offsets 0-based.
-    lineno = -1
-    end_lineno = -1
-    col_offset = -1
-    end_col_offset = -1
-
-
 class _VariableFoundFromToken(object):
     def __init__(
         self, completion_context, variable_token, variable_value, variable_name=None
@@ -72,6 +53,9 @@ def col_offset(self):
     def end_col_offset(self):
         return self.variable_token.end_col_offset
 
+    def __typecheckself__(self) -> None:
+        _: IVariableFound = check_implements(self)
+
 
 class _VariableFoundFromPythonAst(object):
     def __init__(
@@ -89,7 +73,7 @@ def __init__(
         self.end_lineno = end_lineno
         self.end_col_offset = end_col
 
-        self.completion_context = None
+        self.completion_context: Optional[ICompletionContext] = None
         self._path = path
         self.variable_name = variable_name
         self.variable_value = variable_value
@@ -99,6 +83,9 @@ def __init__(
     def source(self):
         return self._path
 
+    def __typecheckself__(self) -> None:
+        _: IVariableFound = check_implements(self)
+
 
 class _VariableFoundFromSettings(object):
     def __init__(self, variable_name, variable_value):
@@ -127,6 +114,9 @@ def col_offset(self):
     def end_col_offset(self):
         return 0
 
+    def __typecheckself__(self) -> None:
+        _: IVariableFound = check_implements(self)
+
 
 class _VariableFoundFromBuiltins(_VariableFoundFromSettings):
     pass
@@ -230,7 +220,7 @@ def _collect_completions_from_ast(
 
 
 def _collect_current_doc_variables(
-    completion_context: ICompletionContext, collector: _Collector
+    completion_context: ICompletionContext, collector: IVariablesCollector
 ):
     """
     :param CompletionContext completion_context:
@@ -242,16 +232,18 @@ def _collect_current_doc_variables(
 
 
 def _collect_resource_imports_variables(
-    completion_context: ICompletionContext, collector: _Collector
+    completion_context: ICompletionContext, collector: IVariablesCollector
 ):
-    resource_doc: IRobotDocument
-    for resource_doc in completion_context.get_resource_imports_as_docs():
+    resource_doc: Optional[IRobotDocument]
+    for _node, resource_doc in completion_context.get_resource_imports_as_docs():
+        if resource_doc is None:
+            continue
         new_ctx = completion_context.create_copy(resource_doc)
         _collect_following_imports(new_ctx, collector)
 
 
 def _collect_variable_imports_variables(
-    completion_context: ICompletionContext, collector: _Collector
+    completion_context: ICompletionContext, collector: IVariablesCollector
 ):
     variable_import_doc: IRobotDocument
     for variable_import_doc in completion_context.get_variable_imports_as_docs():
@@ -315,7 +307,7 @@ def _collect_variable_imports_variables(
 
 
 def _collect_following_imports(
-    completion_context: ICompletionContext, collector: _Collector
+    completion_context: ICompletionContext, collector: IVariablesCollector
 ):
     completion_context.check_cancelled()
     if completion_context.memo.follow_import_variables(completion_context.doc.uri):
@@ -328,7 +320,9 @@ def _collect_following_imports(
         _collect_variable_imports_variables(completion_context, collector)
 
 
-def _collect_arguments(completion_context: ICompletionContext, collector: _Collector):
+def _collect_arguments(
+    completion_context: ICompletionContext, collector: IVariablesCollector
+):
     from robotframework_ls.impl import ast_utils
 
     current_token_info = completion_context.get_current_token()
@@ -352,7 +346,7 @@ def _convert_name_to_var(variable_name):
 
 
 def _collect_from_settings(
-    completion_context: ICompletionContext, collector: _Collector
+    completion_context: ICompletionContext, collector: IVariablesCollector
 ):
     from robotframework_ls.impl.robot_lsp_constants import OPTION_ROBOT_VARIABLES
 
@@ -366,7 +360,7 @@ def _collect_from_settings(
 
 
 def _collect_from_builtins(
-    completion_context: ICompletionContext, collector: _Collector
+    completion_context: ICompletionContext, collector: IVariablesCollector
 ):
     from robotframework_ls.impl.robot_constants import BUILTIN_VARIABLES
 
@@ -376,7 +370,9 @@ def _collect_from_builtins(
             collector.on_variable(_VariableFoundFromBuiltins(key, val))
 
 
-def collect_variables(completion_context: ICompletionContext, collector: _Collector):
+def collect_variables(
+    completion_context: ICompletionContext, collector: IVariablesCollector
+):
     from robotframework_ls.impl import ast_utils
 
     token_info = completion_context.get_current_token()
diff --git a/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis.py b/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis.py
index d36e5454b1..401ee54666 100644
--- a/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis.py
+++ b/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis.py
@@ -206,8 +206,23 @@ def test_resource_does_not_exist(workspace, libspec_manager, data_regression):
     from robotframework_ls.robot_config import RobotConfig
 
     config = RobotConfig()
-    # Note: we don't give errors if we can't resolve a resource.
-    _collect_errors(workspace, doc, data_regression, basename="no_error", config=config)
+    _collect_errors(workspace, doc, data_regression, config=config)
+
+
+def test_report_wrong_library(workspace, libspec_manager, data_regression):
+    workspace.set_root("case4", libspec_manager=libspec_manager)
+    doc = workspace.put_doc(
+        "case4.robot",
+        """*** Settings ***
+Library    DoesNotExist
+Resource    DoesNotExist
+""",
+    )
+
+    from robotframework_ls.robot_config import RobotConfig
+
+    config = RobotConfig()
+    _collect_errors(workspace, doc, data_regression, config=config)
 
 
 def test_casing_on_filename(workspace, libspec_manager, data_regression):
diff --git a/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis/test_report_wrong_library.yml b/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis/test_report_wrong_library.yml
new file mode 100644
index 0000000000..4ec8310c66
--- /dev/null
+++ b/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis/test_report_wrong_library.yml
@@ -0,0 +1,20 @@
+- message: 'Unresolved resource: DoesNotExist'
+  range:
+    end:
+      character: 24
+      line: 2
+    start:
+      character: 12
+      line: 2
+  severity: 1
+  source: robotframework
+- message: 'Unresolved library: DoesNotExist'
+  range:
+    end:
+      character: 23
+      line: 1
+    start:
+      character: 11
+      line: 1
+  severity: 1
+  source: robotframework
diff --git a/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis/test_resource_does_not_exist.yml b/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis/test_resource_does_not_exist.yml
new file mode 100644
index 0000000000..33dffad58a
--- /dev/null
+++ b/robotframework-ls/tests/robotframework_ls_tests/test_code_analysis/test_resource_does_not_exist.yml
@@ -0,0 +1,110 @@
+- message: 'Unresolved resource: does_not_exist.txt'
+  range:
+    end:
+      character: 30
+      line: 5
+    start:
+      character: 12
+      line: 5
+  severity: 1
+  source: robotframework
+- message: 'Unresolved resource: ${foo}/does_not_exist.txt'
+  range:
+    end:
+      character: 37
+      line: 6
+    start:
+      character: 12
+      line: 6
+  severity: 1
+  source: robotframework
+- message: 'Unresolved resource: ../does_not_exist.txt'
+  range:
+    end:
+      character: 33
+      line: 7
+    start:
+      character: 12
+      line: 7
+  severity: 1
+  source: robotframework
+- message: 'Unresolved resource: .'
+  range:
+    end:
+      character: 13
+      line: 8
+    start:
+      character: 12
+      line: 8
+  severity: 1
+  source: robotframework
+- message: 'Unresolved resource: ..'
+  range:
+    end:
+      character: 14
+      line: 9
+    start:
+      character: 12
+      line: 9
+  severity: 1
+  source: robotframework
+- message: 'Unresolved resource: ../'
+  range:
+    end:
+      character: 15
+      line: 10
+    start:
+      character: 12
+      line: 10
+  severity: 1
+  source: robotframework
+- message: 'Unresolved resource: ../../does_not_exist.txt'
+  range:
+    end:
+      character: 36
+      line: 11
+    start:
+      character: 12
+      line: 11
+  severity: 1
+  source: robotframework
+- message: 'Unresolved library: DoesNotExist'
+  range:
+    end:
+      character: 23
+      line: 1
+    start:
+      character: 11
+      line: 1
+  severity: 1
+  source: robotframework
+- message: 'Unresolved library: .'
+  range:
+    end:
+      character: 12
+      line: 2
+    start:
+      character: 11
+      line: 2
+  severity: 1
+  source: robotframework
+- message: 'Unresolved library: ..'
+  range:
+    end:
+      character: 13
+      line: 3
+    start:
+      character: 11
+      line: 3
+  severity: 1
+  source: robotframework
+- message: 'Unresolved library: ../'
+  range:
+    end:
+      character: 14
+      line: 4
+    start:
+      character: 11
+      line: 4
+  severity: 1
+  source: robotframework