[Bug]: Sync issue - no info on the problem, clicking the error redirects to the dashboard

[AndyScherzinger]

⚠️ Before submitting, please verify the following: ⚠️

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

Bug description

The share dialog is looking incomplete.
...

clicking on it leads you to

clicking on that leads you to
https://cloud.nextcloud.com/apps/dashboard/

there is enough local disk space

The the failure of creating a folder might not be related to insufficient storage

Steps to reproduce

1. Run Desktop Win11 with VFS for c.nc.c

Expected behavior

• Provide more information on why the folder could not be created
• when clicking the notification / activity I would expect to be directed to the file/folder in question (which exists on the server)

Which files are affected by this bug

sensitive info

Operating system

Windows

Which version of the operating system you are running.

Windows 11 Pro latest patch level

Package

Other

Nextcloud Server version

28.0.0 RC3

Nextcloud Desktop Client version

3.10.81 (3.11.0 RC1)

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

Updated to a major version (ex. 3.3.6 to 3.4.0)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

Are you using an external user-backend?

• Default internal user-backend
• LDAP/ Active Directory
• SSO - SAML
• Other

Nextcloud Server logs

No response

Additional info

No response

[allexzander]

Not sure if this is exactly the root cause, but here is what I did to come up with #6285

• Create an empty (0 bytes) file (probably not required, can be any size) and upload it to the server
• Have desktop client VFS mode enabled on Windows, and sync that file so it appears as a placeholder on the disk
• Exit the desktop client
• Remove the file from the server and create a folder with exactly the same name and put any file into it
• Run the desktop client and observe how it is unable to download a file with "Couldn't create placeholder info" error

@mgallien what do you think?