diff --git a/kernel/model/render.go b/kernel/model/render.go
index 8eed06c5319..b6c73080cdc 100644
--- a/kernel/model/render.go
+++ b/kernel/model/render.go
@@ -93,6 +93,10 @@ func renderOutline(heading *ast.Node, luteEngine *lute.Lute) (ret string) {
 }
 
 func renderBlockText(node *ast.Node, excludeTypes []string) (ret string) {
+	if nil == node {
+		return
+	}
+
 	ret = sql.NodeStaticContent(node, excludeTypes, false, false, false, GetBlockAttrsWithoutWaitWriting)
 	ret = strings.TrimSpace(ret)
 	ret = strings.ReplaceAll(ret, "\n", "")
diff --git a/kernel/sql/block.go b/kernel/sql/block.go
index 192d373f7d8..0c98a22a7ff 100644
--- a/kernel/sql/block.go
+++ b/kernel/sql/block.go
@@ -139,6 +139,10 @@ func indexNode(tx *sql.Tx, id string) (err error) {
 
 func NodeStaticContent(node *ast.Node, excludeTypes []string, includeTextMarkATitleURL, includeAssetPath, fullAttrView bool,
 	GetBlockAttrsWithoutWaitWriting func(id string) (ret map[string]string)) string {
+	if nil == node {
+		return ""
+	}
+
 	if ast.NodeAttributeView == node.Type {
 		if fullAttrView {
 			return getAttributeViewContent(node.AttributeViewID, GetBlockAttrsWithoutWaitWriting)
diff --git a/kernel/sql/block_query.go b/kernel/sql/block_query.go
index f0176df3fdf..d723ff71e97 100644
--- a/kernel/sql/block_query.go
+++ b/kernel/sql/block_query.go
@@ -812,6 +812,10 @@ func GetContainerText(container *ast.Node) string {
 	buf := &bytes.Buffer{}
 	buf.Grow(4096)
 	leaf := treenode.FirstLeafBlock(container)
+	if nil == leaf {
+		return ""
+	}
+
 	ast.Walk(leaf, func(n *ast.Node, entering bool) ast.WalkStatus {
 		if !entering {
 			return ast.WalkContinue