[Bug]: Call to a member function instanceOfStorage() on null

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Last month in logs I have started to observe erorrs and warning:
``
[index] Error: Call to a member function instanceOfStorage() on null in file '/var/www/html/nextcloud/apps/files_sharing/lib/Cache.php' line 70
GET /index.php/apps/files/files/***?dir=/Shared/myfolder
from **** user username on 13 Sep 2025 at 00:00:00

[no app in context] Warning: Possible share setup recursion detected
GET /index.php/apps/files/files/***?dir=/Shared/myfolder
from **** user username on 13 Sep 2025 at 00:00:00

``

Steps to reproduce

1. Use file sharing
2. Share a some folder
3. Observe above mentioned errors

Expected behavior

No errors to be observed

Nextcloud Server version

30

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.3-fpm

Web server

Apache (supported)

Database engine version

MariaDB

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

List of activated Apps

Nextcloud Signing status

Nextcloud Logs

{"reqId":"*****","level":3,"time":"2025-09-13T16:34:41+03:00","remoteAddr":"*****","user":"username","app":"index","method":"GET","url":"/index.php/apps/files/files/***?dir=/Shared/myfolder","message":"Call to a member function instanceOfStorage() on null in file '/www/html/nextcloud/apps/files_sharing/lib/Cache.php' line 70","userAgent":"Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36","version":"30.0.15.1","exception":{"Exception":"Exception","Message":"Call to a member function instanceOfStorage() on null in file '/www/html/nextcloud/apps/files_sharing/lib/Cache.php' line 70","Code":0,"Trace":[{"file":"/www/html/nextcloud/lib/private/AppFramework/App.php","line":161,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/www/html/nextcloud/lib/private/Route/Router.php","line":303,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/www/html/nextcloud/lib/base.php","line":1032,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/www/html/nextcloud/index.php","line":24,"function":"handleRequest","class":"OC","type":"::"}],"File":"/www/html/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","Line":146,"Previous":{"Exception":"Error","Message":"Call to a member function instanceOfStorage() on null","Code":0,"Trace":[{"file":"/www/html/nextcloud/lib/private/Files/Cache/Wrapper/CacheJail.php","line":63,"function":"getRoot","class":"OCA\\Files_Sharing\\Cache","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Cache/Wrapper/CacheJail.php","line":141,"function":"getSourcePath","class":"OC\\Files\\Cache\\Wrapper\\CacheJail","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Cache/Wrapper/CacheWrapper.php","line":149,"function":"getId","class":"OC\\Files\\Cache\\Wrapper\\CacheJail","type":"->"},{"file":"/www/html/nextcloud/apps/workflowengine/lib/Check/FileSystemTags.php","line":155,"function":"getId","class":"OC\\Files\\Cache\\Wrapper\\CacheWrapper","type":"->"},{"file":"/www/html/nextcloud/apps/workflowengine/lib/Check/FileSystemTags.php","line":106,"function":"getFileIds","class":"OCA\\WorkflowEngine\\Check\\FileSystemTags","type":"->"},{"file":"/www/html/nextcloud/apps/workflowengine/lib/Check/FileSystemTags.php","line":66,"function":"getSystemTags","class":"OCA\\WorkflowEngine\\Check\\FileSystemTags","type":"->"},{"file":"/www/html/nextcloud/apps/workflowengine/lib/Service/RuleMatcher.php","line":224,"function":"executeCheck","class":"OCA\\WorkflowEngine\\Check\\FileSystemTags","type":"->"},{"file":"/www/html/nextcloud/apps/workflowengine/lib/Service/RuleMatcher.php","line":159,"function":"check","class":"OCA\\WorkflowEngine\\Service\\RuleMatcher","type":"->"},{"file":"/www/html/nextcloud/apps/workflowengine/lib/Service/RuleMatcher.php","line":107,"function":"getMatchingOperations","class":"OCA\\WorkflowEngine\\Service\\RuleMatcher","type":"->"},{"file":"/www/html/nextcloud/apps/files_accesscontrol/lib/Operation.php","line":71,"function":"getFlows","class":"OCA\\WorkflowEngine\\Service\\RuleMatcher","type":"->"},{"file":"/www/html/nextcloud/apps/files_accesscontrol/lib/CacheWrapper.php","line":36,"function":"checkFileAccess","class":"OCA\\FilesAccessControl\\Operation","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Cache/Wrapper/CacheWrapper.php","line":72,"function":"formatCacheEntry","class":"OCA\\FilesAccessControl\\CacheWrapper","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Node/Root.php","line":474,"function":"get","class":"OC\\Files\\Cache\\Wrapper\\CacheWrapper","type":"->"},{"function":"OC\\Files\\Node\\{closure}","class":"OC\\Files\\Node\\Root","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/www/html/nextcloud/lib/private/Files/Node/Root.php","line":472,"function":"array_map"},{"file":"/www/html/nextcloud/lib/private/Files/Node/LazyFolder.php","line":475,"function":"getByIdInPath","class":"OC\\Files\\Node\\Root","type":"->"},{"file":"/www/html/nextcloud/apps/files_sharing/lib/SharedStorage.php","line":150,"function":"getById","class":"OC\\Files\\Node\\LazyFolder","type":"->"},{"file":"/www/html/nextcloud/apps/files_sharing/lib/SharedStorage.php","line":554,"function":"init","class":"OCA\\Files_Sharing\\SharedStorage","type":"->"},{"function":"getSourceStorage","class":"OCA\\Files_Sharing\\SharedStorage","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php","line":509,"function":"call_user_func_array"},{"function":"__call","class":"OC\\Files\\Storage\\Wrapper\\Wrapper","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php","line":509,"function":"call_user_func_array"},{"file":"/www/html/nextcloud/apps/files_sharing/lib/Cache.php","line":85,"function":"__call","class":"OC\\Files\\Storage\\Wrapper\\Wrapper","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Cache/Wrapper/CacheWrapper.php","line":70,"function":"getCache","class":"OCA\\Files_Sharing\\Cache","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Cache/Wrapper/CacheJail.php","line":108,"function":"get","class":"OC\\Files\\Cache\\Wrapper\\CacheWrapper","type":"->"},{"file":"/www/html/nextcloud/apps/files_sharing/lib/Cache.php","line":108,"function":"get","class":"OC\\Files\\Cache\\Wrapper\\CacheJail","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Cache/Wrapper/CacheWrapper.php","line":70,"function":"get","class":"OCA\\Files_Sharing\\Cache","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Node/Root.php","line":474,"function":"get","class":"OC\\Files\\Cache\\Wrapper\\CacheWrapper","type":"->"},{"function":"OC\\Files\\Node\\{closure}","class":"OC\\Files\\Node\\Root","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/www/html/nextcloud/lib/private/Files/Node/Root.php","line":472,"function":"array_map"},{"file":"/www/html/nextcloud/lib/private/Files/Node/Root.php","line":406,"function":"getByIdInPath","class":"OC\\Files\\Node\\Root","type":"->"},{"file":"/www/html/nextcloud/lib/private/Files/Node/LazyFolder.php","line":479,"function":"getFirstNodeByIdInPath","class":"OC\\Files\\Node\\Root","type":"->"},{"file":"/www/html/nextcloud/apps/files/lib/Controller/ViewController.php","line":221,"function":"getFirstNodeById","class":"OC\\Files\\Node\\LazyFolder","type":"->"},{"file":"/www/html/nextcloud/apps/files/lib/Controller/ViewController.php","line":135,"function":"redirectToFileIfInTrashbin","class":"OCA\\Files\\Controller\\ViewController","type":"->"},{"file":"/www/html/nextcloud/apps/files/lib/Controller/ViewController.php","line":121,"function":"index","class":"OCA\\Files\\Controller\\ViewController","type":"->"},{"file":"/www/html/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":208,"function":"indexViewFileid","class":"OCA\\Files\\Controller\\ViewController","type":"->"},{"file":"/www/html/nextcloud/lib/private/AppFramework/Http/Dispatcher.php","line":114,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/www/html/nextcloud/lib/private/AppFramework/App.php","line":161,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->"},{"file":"/www/html/nextcloud/lib/private/Route/Router.php","line":303,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/www/html/nextcloud/lib/base.php","line":1032,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/www/html/nextcloud/index.php","line":24,"function":"handleRequest","class":"OC","type":"::"}],"File":"/www/html/nextcloud/apps/files_sharing/lib/Cache.php","Line":70},"message":"Call to a member function instanceOfStorage() on null in file '/www/html/nextcloud/apps/files_sharing/lib/Cache.php' line 70","exception":[],"CustomMessage":"Call to a member function instanceOfStorage() on null in file '/www/html/nextcloud/apps/files_sharing/lib/Cache.php' line 70"},"id":"68c5bdccd5570"}

Additional info

No response

Start at apps/files_sharing/lib/Cache.php line 70 and trace the reported call through the files_sharing, workflowengine, files_accesscontrol, and files entry points shown in the stack trace. Reproduce the error by opening a shared folder, then determine why the storage object is null. Done means shared-folder access no longer logs the error or recursion warning.