[Bug]: Issue with File Corruption on Windows 10 After Syncing Large Data via Nextcloud Client

[Cocean001]

⚠️ Before submitting, please verify the following: ⚠️

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

Bug description

Hi,

I have a problem with the Nextcloud client on Windows 10. I used Docker to deploy Nextcloud and tried to sync a large folder (over 500 GB, mostly video files) from my Windows machine to Nextcloud. My Nextcloud instance was totally empty before syncing.

After the sync, some files on my Windows machine are corrupted and can't be used, even though the files on the Nextcloud server are fine. I've noticed that the files having issues on my local machine show a Nextcloud syncing logo, unlike the files without problems.

I'm not sure what's causing this or how to fix it. I would appreciate any help or suggestions on this matter.

Thanks.

Steps to reproduce

1. Deploy a new Nextcloud instance using Docker.
2. On a Windows 10 machine, install the Nextcloud client.
3. Choose a large folder (over 500GB, predominantly video files) for synchronization.
4. Begin the synchronization process from the Nextcloud client.
5. Wait for the synchronization to complete.
6. Inspect files on the Windows machine post-sync.

Expected behavior

All local files remain intact post-sync, and their copies on the Nextcloud server are perfectly synced without causing any local file corruption.

Which files are affected by this bug

multiple files are affected

Operating system

Windows

Which version of the operating system you are running.

Windows 10

Package

Appimage

Nextcloud Server version

latest

Nextcloud Desktop Client version

latest

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

Updated from a minor version (ex. 3.4.2 to 3.4.4)

Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

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

[joshtrichards]

Hi @Cocean001 - Are you still experiencing this? If so:

• What version of the client specifically?
• Are you willing to provide debug logs?

From the sounds of it, those files weren't fully synced so perhaps we were reporting the wrong overall state.