[Bug]: overlay icons missing from Windows Explorer if another user account is logged in / another instance of Nextcloud client is running (with VFS)

[PhilippSchlesinger]

⚠️ 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

Overlay icons like the share icon (marked green) are missing

in Windows Explorer if Windows account is logged in already.
Virtual files are activated.

This bug report is a byproduct of the comment in that bug #5301 (comment) and behaves in the same way.
I suppose the solution will be analogous.

Steps to reproduce

1. Log into a first Windows user account with Nextcloud Client installed and check that overlay icons are shown.
2. Log into a second Windows user account and check the Nextcloud folder. No overlay icons (like the share icon) are shown.

Expected behavior

Overlay icons should show for every user account on the Windows system, even if another account is logged in already.

Which files are affected by this bug

x

Operating system

Windows

Which version of the operating system you are running.

Windows 10

Package

Distro package manager

Nextcloud Server version

26.0.6

Nextcloud Desktop Client version

3.10.0

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

(I could reproduce the issue on at least different Windows systems)

[PhilippSchlesinger]

An additional note: It is sufficient to ensure that only one instance of Nextcloud is running at the same time on a Windows system.
Therefore, if you close the Nextcloud Client on a Windows account and then start the Nextcloud Client on a different account, the display of overlay icons (like the share icon) will work there.

@allexzander, @mgallien Does the issue relate to the way in which the overlay shell extension registers itself with Windows Explorer?