diff --git a/composer.lock b/composer.lock
index 760c6b5e8..15e8c41fb 100644
--- a/composer.lock
+++ b/composer.lock
@@ -696,16 +696,17 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/nextcloud-deps/ocp.git",
-                "reference": "bf16e87ef27d0c3d5812cc2352ecf50f2b96e669"
+                "reference": "5c5b6d8600ddaf9f466736e34103b2921cc9b0e3"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/nextcloud-deps/ocp/zipball/bf16e87ef27d0c3d5812cc2352ecf50f2b96e669",
-                "reference": "bf16e87ef27d0c3d5812cc2352ecf50f2b96e669",
+                "url": "https://api.github.com/repos/nextcloud-deps/ocp/zipball/5c5b6d8600ddaf9f466736e34103b2921cc9b0e3",
+                "reference": "5c5b6d8600ddaf9f466736e34103b2921cc9b0e3",
                 "shasum": ""
             },
             "require": {
                 "php": "^7.4 || ~8.0 || ~8.1",
+                "psr/clock": "^1.0",
                 "psr/container": "^1.1.1",
                 "psr/event-dispatcher": "^1.0",
                 "psr/log": "^1.1"
@@ -732,7 +733,7 @@
                 "issues": "https://github.com/nextcloud-deps/ocp/issues",
                 "source": "https://github.com/nextcloud-deps/ocp/tree/master"
             },
-            "time": "2022-12-17T00:35:01+00:00"
+            "time": "2023-02-09T00:37:24+00:00"
         },
         {
             "name": "nikic/php-parser",
@@ -1457,6 +1458,54 @@
             },
             "time": "2016-08-06T20:24:11+00:00"
         },
+        {
+            "name": "psr/clock",
+            "version": "1.0.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/php-fig/clock.git",
+                "reference": "e41a24703d4560fd0acb709162f73b8adfc3aa0d"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/php-fig/clock/zipball/e41a24703d4560fd0acb709162f73b8adfc3aa0d",
+                "reference": "e41a24703d4560fd0acb709162f73b8adfc3aa0d",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.0 || ^8.0"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Psr\\Clock\\": "src/"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "PHP-FIG",
+                    "homepage": "https://www.php-fig.org/"
+                }
+            ],
+            "description": "Common interface for reading the clock.",
+            "homepage": "https://github.com/php-fig/clock",
+            "keywords": [
+                "clock",
+                "now",
+                "psr",
+                "psr-20",
+                "time"
+            ],
+            "support": {
+                "issues": "https://github.com/php-fig/clock/issues",
+                "source": "https://github.com/php-fig/clock/tree/1.0.0"
+            },
+            "time": "2022-11-25T14:36:26+00:00"
+        },
         {
             "name": "psr/container",
             "version": "1.1.2",
diff --git a/lib/ACL/ACLManager.php b/lib/ACL/ACLManager.php
index 316e850f0..21718a8f6 100644
--- a/lib/ACL/ACLManager.php
+++ b/lib/ACL/ACLManager.php
@@ -49,7 +49,7 @@ private function getRootStorageId(): int {
 			$provider = $this->rootFolderProvider;
 			/** @var IRootFolder $rootFolder */
 			$rootFolder = $provider();
-			$this->rootStorageId = $rootFolder->getMountPoint()->getNumericStorageId();
+			$this->rootStorageId = $rootFolder->getMountPoint()->getNumericStorageId() ?? -1;
 		}
 
 		return $this->rootStorageId;
diff --git a/lib/ACL/ACLStorageWrapper.php b/lib/ACL/ACLStorageWrapper.php
index 0b7026b9b..265496802 100644
--- a/lib/ACL/ACLStorageWrapper.php
+++ b/lib/ACL/ACLStorageWrapper.php
@@ -232,7 +232,7 @@ public function filetype($path) {
 		return parent::filetype($path);
 	}
 
-	public function filesize($path) {
+	public function filesize($path): false|int|float {
 		if (!$this->checkPermissions($path, Constants::PERMISSION_READ)) {
 			return false;
 		}
diff --git a/lib/Controller/FolderController.php b/lib/Controller/FolderController.php
index d7dd65986..d03bfcc88 100644
--- a/lib/Controller/FolderController.php
+++ b/lib/Controller/FolderController.php
@@ -26,6 +26,7 @@
 use OCA\GroupFolders\Mount\MountProvider;
 use OCA\GroupFolders\Service\DelegationService;
 use OCA\GroupFolders\Service\FoldersFilter;
+use OCP\AppFramework\Http;
 use OCP\AppFramework\Http\DataResponse;
 use OCP\AppFramework\OCSController;
 use OCP\Files\IRootFolder;
@@ -84,10 +85,15 @@ public function getFolders(): DataResponse {
 	 * @RequireGroupFolderAdmin
 	 */
 	public function getFolder(int $id): DataResponse {
-		return new DataResponse($this->manager->getFolder($id, $this->getRootFolderStorageId()));
+		$storageId = $this->getRootFolderStorageId();
+		if ($storageId === null) {
+			return new DataResponse([], Http::STATUS_NOT_FOUND);
+		}
+
+		return new DataResponse($this->manager->getFolder($id, $storageId));
 	}
 
-	private function getRootFolderStorageId(): int {
+	private function getRootFolderStorageId(): ?int {
 		return $this->rootFolder->getMountPoint()->getNumericStorageId();
 	}
 
diff --git a/lib/Versions/GroupVersion.php b/lib/Versions/GroupVersion.php
index 9fb2b30b4..6e40fd780 100644
--- a/lib/Versions/GroupVersion.php
+++ b/lib/Versions/GroupVersion.php
@@ -40,7 +40,7 @@ public function __construct(
 		int $timestamp,
 		int $revisionId,
 		string $name,
-		int $size,
+		float|int $size,
 		string $mimetype,
 		string $path,
 		FileInfo $sourceFileInfo,