Shared Document With Watermark - Can't open without a logged-in account.

[gokaysatir]

Describe the bug Tested with a shared link (editable). When the link is used without an active logged-in account, we fail to load the view altogether. This is on NC 23.0.3 with Nextcloud Office 5.0.3. The exception: Error: Argument 1 passed to OC\Group\Manager::getUserIdGroupIds() must be of the type string, null given,

To Reproduce

• Enable water mark for one group: * Share the link. * We check if the user belongs to watermark group or not. richdocuments fails at that point.

Nextcloud version: NC 23.0.3

Version of the richdocuments app 5.0.3