[Bug]: Windows Client Crash when Sync - Errorcode: 0xc0000409

[PaulEDV]

⚠️ 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 Windows client regularly crashes during the first synchronization and does not start automatically afterwards.

This affects several of our clients but not all, regardless of whether Windows 10 22h2 or Windows 11 23h2.
See forum post:
https://help.nextcloud.com/t/windows-desktop-version-crash-when-sync/205224/3

The following message is in the Windows event log:

---

Name der fehlerhaften Anwendung: nextcloud.exe, Version: 3.14.1.55839, Zeitstempel: 0x66f6776f
Name des fehlerhaften Moduls: ucrtbase.dll, Version: 10.0.19041.3636, Zeitstempel: 0x81cf5d89
Ausnahmecode: 0xc0000409
Fehleroffset: 0x000000000007286e
ID des fehlerhaften Prozesses: 0x6240
Startzeit der fehlerhaften Anwendung: 0x01db13e6640a5c1f
Pfad der fehlerhaften Anwendung: C:\Program Files\Nextcloud\nextcloud.exe

Here are the log files of the Nextcloud client and the event log:
nextcloud_log.zip

Steps to reproduce

1. install Nextcloud Client
2. connect Nextcloud Client with the Nextcloud
3. set up Nextcloud Sync with virtual files
4. wait until client crashes unnoticed

Expected behavior

The Nextcloud client should display an error message in the event of a crash or restart automatically after a crash during sync

Which files are affected by this bug

last Sync File in the log is: 20220314_Art der Vergabe - Verknüpfung.lnk

Operating system

Windows

Which version of the operating system you are running.

Windows 10 22H2 an Windows 11 23H2

Package

Official Windows MSI

Nextcloud Server version

29.0.5

Nextcloud Desktop Client version

3.14.1

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

Fresh desktop client install

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

[Killea]

same issue.
down to 3.13.3 worked for me. (I also disabled auto upgrade)
could also try Nextcloud-3.13.4-x64.msi
3.14+ will not work.

[eckgit]

The same issue with Nextcloud-Client-version 3.14.1 in virtual folder mode occured for me in Windows 11 Pro, 10.0.22631, Build 22631.
Will give also version 3.13.3 a try.

[y0umu]

I encountered the same problem even without using the virtual folder mode. Versions are 3.14.0-x64, 3.13.4-x64 on windows.