Permission errors in Sonarr V4

Sonarr version (exact version): 4.0.0.748
Mono version (if Sonarr is not running on Windows): 5.20.1
OS: Synology 7

I’m running Sonarr, Radarr and Sabnzbd on a Synology NAS. Today I’ve updated Sonarr from V3 to V4 by installing the Sonarr V4 community package, and now I am getting a bunch of permission errors plus Sonarr can no longer see the subfolders within my main Series folder.

For example I get this error on the Status page:

And when I press on the /volume1/Series link under Root Folders:

then I get a page that just says Unable to load root folders:

Screenshot 2024-01-19 at 22.13.47

The thing is that I don’t know what user Sonarr is running as, and I don’t know how to fix the folder permissions to make everything work again. When I go the File Station on my NAS and right click on the Series folder, choose Properties and then go to the Permissions tab, I see this:

It seems to me that everything should have read and write access?

And this is what I get for the /volume1/Downloads/complete folder:


I’ll be honest: l don’t know what to do to fix these problems. How should the permissions be set so that all 3 apps can read and write the files as expected?

Logs:

2024-01-19 21:32:03.9|Error|RootFolderService|Unable to get free space and unmapped folders for root folder /volume1/Series/

[v4.0.0.748] System.UnauthorizedAccessException: Access to the path '/volume1/Series' is denied.
 ---> System.IO.IOException: Permission denied
   --- End of inner exception stack trace ---
   at System.IO.Enumeration.FileSystemEnumerator`1.CreateDirectoryHandle(String path, Boolean ignoreNotFound)
   at System.IO.Enumeration.FileSystemEnumerator`1.Init()
   at System.IO.Enumeration.FileSystemEnumerable`1..ctor(String directory, FindTransform transform, EnumerationOptions options, Boolean isNormalized)
   at System.IO.Enumeration.FileSystemEnumerableFactory.UserDirectories(String directory, String expression, EnumerationOptions options)
   at System.IO.Directory.InternalEnumeratePaths(String path, String searchPattern, SearchTarget searchTarget, EnumerationOptions options)
   at System.IO.Directory.EnumerateDirectories(String path)
   at NzbDrone.Common.Disk.DiskProviderBase.GetDirectories(String path) in ./Sonarr.Common/Disk/DiskProviderBase.cs:line 156
   at NzbDrone.Core.RootFolders.RootFolderService.GetUnmappedFolders(String path, Dictionary`2 seriesPaths) in ./Sonarr.Core/RootFolders/RootFolderService.cs:line 146
   at NzbDrone.Core.RootFolders.RootFolderService.<>c__DisplayClass14_0.<GetDetails>b__0() in ./Sonarr.Core/RootFolders/RootFolderService.cs:line 210
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)

I’ve updated Mono to version 6.12.0, I’ve restarted the NAS, I’ve looked all through the different permission settings on the folders, all without any success. I still get the same permission errors in Sonarr.

Weirdly enough Radarr isn’t complaining at all. How can it be that Radarr says “No issues with your configuration” while Sonarr says “Download client Sabnzbd places downloads in /volume1/Downloads/complete but Sonarr cannot see this directory”?