WebDAV Sync Error 909974 After Multi-Device Setup with Apache on Windows

[MikeH]

Hi Enpass team, or other Enpass users -

Are you guys (Enpass team) sure Enpass works with a local, non-cloud, vault?  After being stuck for several months on the WiFi sync issue in my other ticket I though I would give a self-hosted WebDAV a try.  But it has showstopper issues also.  Do you consider a self-hosted vault to be a mainstream configuration?  I thought that is your main differentiator -- it is the most important feature for me.

I'm encountering persistent sync failures with Enpass using a self-hosted WebDAV server. The error code is 909974 on vault sync on my Windows 11 server, which appears after a second device attempts to sync or modify the vault. Here's a breakdown of my setup and the issue:

Setup:

• Server OS: Windows 11
• WebDAV Server: Apache 2.4.65 (installed as a Windows service)
• Vault Location: C:\Apache24\webdav\enpassvault\Enpass\
• DavLockDB: Configured as C:/Apache24/var/DavLock
• Authentication: Basic Auth via AuthUserFile
• Apache Config Includes:

Alias /enpassvault "C:/Apache24/webdav/enpassvault"

<Directory "C:/Apache24/webdav/enpassvault">
    Dav On
    AuthType Basic
    AuthName "Enpass Vault"
    AuthUserFile "C:/Apache24/conf/user.passwd"
    Require valid-user
    Options Indexes
    <LimitExcept GET OPTIONS>
        Require valid-user
    </LimitExcept>
</Directory>

 

Devices Connected:

• Windows 11 laptop
• Linux Mint desktop
• iPhone

What Works:

• Initial sync from one device (e.g., Linux) works fine
• Vault is created and accessible via browser and WebDAV clients
• Apache logs show successful PROPFIND, GET, and MKCOL operations

What Fails:

• After a second device (e.g., laptop or server) attempts to sync, Enpass throws error 909974
• Apache logs show successful access to vault.enpassdbsync, but Enpass fails to reconcile changes
• Error persists even after restarting Apache and clearing the lock database

Troubleshooting Steps Already Taken:

• Recreated the vault folder and let Enpass initialize it cleanly
• Verified folder permissions and Apache access across all parent directories
• Confirmed DavLockDB is writable and active
• Ensured only one device syncs at a time during reinitialization
• Tested access via browser — no issues observed

Request:

Can you clarify what triggers error 909974 in multi-device WebDAV setups? Is there a known issue with Apache’s locking or file overwrite behavior that Enpass expects? Are there specific WebDAV methods or headers Enpass requires that Apache may not fully support?

Any guidance on how to stabilize sync across multiple devices would be greatly appreciated.

Thanks,

Mike

 

[Amandeep Kumar]

Thank you for sharing the detailed information about your setup and the troubleshooting steps you’ve already taken. I will pass this along to our technical team for further investigation. If we need any additional details from you, we’ll reach out.

We truly appreciate your patience as we work to resolve this issue!
#SI-4490