OneDrive error 0x8004DEF4 on one RDS Session Host only

Question

OneDrive error 0x8004DEF4 on one RDS Session Host only

Dom 0

Environment:

Windows Server 2025
2x RDS Session Hosts
WTS1 is also Connection Broker
WTS2 has Microsoft Entra Connect Synchronization Services (Azure AD Connect) running (not optimal i know)
FSLogix Profile Containers
OneDrive for Business
Microsoft 365 Apps
Apps and Windows Versions are identical
System is running for over a year now

Problem:

Users received OneDrive error 0x8004DEF4 only on WTS2, about a week ago for the first time

The same users work fine on WTS1.

What has already been done:

Office Online Repair
OneDrive completely removed and reinstalled
Same OneDrive version on both hosts
Same Office version on both hosts
No relevant errors in Application/System logs
AAD 1098 TokenBroker errors exist on BOTH hosts
FSLogix profiles are shared between both hosts
GPOs are identical
Disconnecting user from all active sessions in MS365 administration
bot devices are AzureADjoined
deleted onedrive folder under appdata for a user on both devices

Interesting observation:

Deleting %localappdata%\Microsoft\OneDrive\settings immediately fixes the issue on WTS2

If users stay on, or get reconnected to WTS2, OneDrive continues to work fine

The issue becomes reproducible when:

User signs in to WTS2
OneDrive works
User signs in to WTS1 (onedrive always works here, no error ever)
User returns to WTS2
OneDrive throws 0x8004DEF4 again

I can reproduce this repeatedly.

No triggering event could be identified.

There were no corresponding changes around the time the problem began:

No recent Windows updates (latest September Updates installed on Sept. 12th)
No recent Office updates
No recent OneDrive deployment
No recent Entra Connect installation or update
No recent GPO changes

Application and System event logs were reviewed and do not contain any errors that correlate with the onset of the issue.

The only recurring errors found were AAD Event ID 1098 entries, however these occur on both WTS1 and WTS2 and therefore do not appear to be related to the issue.

Sorry for the long post, but me and copilot are at the end of the road. I don't know what to do anymore. Please help.

0 comments

2 answers

Your answer

Answer 1

Dom 0

Hi there!

Thx for the answer first of all!

HKLM\SOFTWARE\FSLogix\Profiles\ IncludeOneDrive - does not exist on both wts - all other entries are identical

I saved the log folder after the error, but to be honest, i have no clue what to do with the odl files or the sync-log.

0 comments

Answer 2

Hello Dom,

Sorry to hear you're facing a tough issue. Here are my analysis and suggestions:

The strongest lead is the FSLogix-roamed OneDrive state, not the OneDrive installation. Microsoft explicitly states that IncludeOneDrive=1 redirects the OneDrive cache into the profile container, but OneDrive does not support multiple simultaneous connections using the same profile, which closely matches your WTS1 → WTS2 reproduction pattern.

I would first verify HKLM\SOFTWARE\FSLogix\Profiles\IncludeOneDrive and the FSLogix version/configuration on both hosts, then reproduce the issue with a brand-new FSLogix profile. If the new profile works across WTS1/WTS2, the existing container's OneDrive/identity state is the likely culprit; Microsoft confirms that OneDrive, TokenBroker, OneAuth and IdentityCache can reside in FSLogix-managed profile data.

When the error occurs, do not immediately delete settings; collect %LocalAppData%\Microsoft\OneDrive\logs first, then use the settings reset as a workaround. Microsoft confirms 0x8004DEF4 can have several causes, so the logs are needed before identifying a definitive root cause. I would also move Entra Connect off WTS2 when possible, although there is currently insufficient evidence to call it the cause.

Let me know if it works.