FSLogix Troubleshooting guide

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This article will cover some common issues I have ran into, and steps on how to resolve them.

The guide should be followed in order since most of the advanced items are usually not the cause of a problem.

If you just set up FSLogix, make sure that you followed every step under Deploying FSLogix Office 365 Containers and Deploying FSLogix Profile Containers


  • ODFC = Office Data File Containers
    • This is there Office (Outlook, Teams, Licensing) data is stored
    • This can be used in conjunction with UPDs
  • FSL Profiles
    • Replacement for UPDs
    • User profiles are stored here (Office data is stored in the ODFC)
    • Cannot be used in conjunction with UPDs


The items below should be ignored when troubleshooting
  • Local_ files under C:\Users
    • If FSLogix profiles are enabled, these folders can be ignored. They will be deleted the next time the user signs in.

Basic Checks

Before troubleshooting any specific items you need to verify that all of the items below are in order.

  • FSLogix Drive space on the file server
    • The drive should have at least 5-10 GB available
  • Make sure that you can reach the share while logged in as the user experiencing the issue
    • Make sure that you can access the share from the RDS having the issue. Generally a DFS path is used.
  • Make sure that the affected user has full control and Owner over their FSLogix Folder and the VHDX files.
  • Make sure that the FSL VHDX is not out of space
    • Profiles:
      • Open "C:\Program Files\FSLogix\Apps\frxtray.exe"
      • Check the "Remaining Space" Field
    • Office Containers:
      • Navigate to the FSL disk of the user and check the size of the disk. If it is at 49.9, 19.9, or anything close to a whole number then it might be out of space.
    • Follow the steps on the Adding Space to FSL section if it is out of space
  • Make sure that the user is not being excluded from FSLogix
    • Check the local groups on the RDS, and make sure that they line up with what you're expecting.
    • Generally "Everyone" should be part of the include lists, and the Exclude list should be empty*
      • *Sometimes the Exclude list will have a Domain group called APP_FSLogix_Exclude. Check that group in AD to make sure that it does not have any members.
  • Is there a .old file on the user's FSL folder?
    • FSL will open the first VHDX that matches the string it's looking for. Adding .old at the end does not stop it from loading a VHDX. 
    • Remove or significantly rename (Add OLD to the front of the file) any files that do not belong

FSL Disk Keeps running out of Space

  • Make sure that the user has a 3 Month caching policy applied to them
  • Make sure that there are no old OSTs under %localappdata%\Microsoft\Outlook
  • Make sure that the user is not storing data on the root of their profile folder (C:\Users\Example)

Search Issues

FSLogix should not be set to roam the windows search on Server 2019. Make sure it is disabled in the settings below.
  • Server 2019 Only:
    • Make sure that FSLogix is not configured to roam the Windows Search. The keys below should be deleted or set to 0.
      • HKEY_LOCAL_MACHINE\SOFTWARE\FSLogix\Profiles\RoamSearch
      • HKEY_LOCAL_MACHINE\SOFTWARE\Policies\FSLogix\ODFC\RoamSearch
    • Restart the server after the changes
  • None of the items below apply to 2019 since FSL should not be interacting with the search service.
  • Make sure that the Windows Search Service is running
  • Re-build the search index if you have not done so already
  • Make sure that office was installed after the search service was installed. If you're unsure then re-install office
  • Make sure that the search service starts after the FSLogix Service

Stuck VHDX

This section addresses the following issues:
  • Black Screen at logon for 1-3 minutes
  • Chrome Bookmarks missing
  • Outlook cache missing
  • Task bar buttons missing
  • Profile is missing customizations (new profile)
  • Office asking for activation (generally not an FSL issue, but still a symptom)
  • All of the issues above persisting even after logging out and back in
The issues above are generally caused by the FSL VHDX file getting stuck somewhere. Follow the steps below to unlock it:
  1. Log the user out of the RDS server
  2. Go to the file server and open Computer manager (compmgmt.msc)
  3. Click on Shared Folders/Open Files
  4. Close all open files by the affected user
  5. Log the user back in and the session should open quickly with all of the user's data
  6. If that does not resolve the issue move to the next step

User Has a new Profile

  1. Check the user's FSL folder and inspect the size of their Profile_.VHDX file
  2. Is it less than 450MB in size?
  3. If so, the VHDX might have been corrupt and a new one was created. 
  4. Restore the VHDX file from backup
    1. Make sure that the file you are restoring is larger than the one you have now, otherwise this might not be the issue.
    2. If you restore from backup make sure that the permissions are corrected

Advanced Checks

  • Make sure that UPDs and FSLogix Profiles are not enabled at the same time
    • If both of the keys below are set to 1 then there is a major misconfiguration. If one does not exist or it's set to 0 then move onto the next step.
      • HKEY_LOCAL_MACHINE\SOFTWARE\FSLogix\Profiles\Enabled
      • HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Terminal Server\ClusterSettings\UvhdEnabled
    • If both keys were set to 1 then there is a high probability that the FSLogix profile VHDX files will need to be restored from backup.
  • Make sure that the FSLogix license has not expired
    • Navigate to %PROGRAMDATA%\FSLogix\Logs\ODFC or %PROGRAMDATA%\FSLogix\Logs\Profile
    • Open the most recent file and make sure that it does not say "License Has Expired" at the top
    • To install the correct key:
      • "c:\program files\fslogix\apps\frx.exe" set-key -key MSFT0-YXKIX-NVQI4-I6WIA-O4TXE
  • Is AutoHotKey in use? I have seen an issue where anyone that uses AutoHotKey gets a stuck profile every few days. Removing the application resolved the issue. 

Check the Logs

Before going deeper it is a good idea to check the FSL logs.
  1. Navigate to %PROGRAMDATA%\FSLogix\Logs\ODFC or %PROGRAMDATA%\FSLogix\Logs\Profile
  2. Open the most recent file and find any ERRORs or WARNINGs. Many times it will tell you exactly what the issue is

Log Says "Container is already attached for another session"

Follow Solution 2 here: https://wilkyit.com/2017/07/10/fslogix-error-vhd-fails-to-attach-container-is-already-attached-for-another-session/

Only remove the key for the user experiencing the issue

Broken Profile When Signing In

The steps below should only be followed if the following conditions are met:
  • You are still seeing issues even after following all of the previous steps
  • Logging the user back in produces an odd folder under c:\users (.BACKUP, User.0, .DOMAIN.000, etc.)
  1. Log the user out of the RDS server
  2. Close any open connections on the RDS
  3. On the RDS, run the command below
    1. "c:\program files\fslogix\apps\frx.exe" list-redirects
  4. Copy the output into notepad for easier analysis
  5. CTRL+F the username of the user. Do they come up somewhere in the output? Follow the steps below.
    1. Run the command below for each line you found with the username
    2. "c:\program files\fslogix\apps\frx.exe" del-redirect -src <Redirpath>
      1. <Redirpath> should be substituted for everything left of the "=>" (see red boxes below)
        1. "c:\program files\fslogix\apps\frx.exe" del-redirect -src \Device\HarddiskVolume2\Users\TestUser
    3. Delete any relevant folders under C:\Users
    4. Log the user back into the RDS
    5. If that does not resolve the issue then the RDS might need to be restarted

Adding Space to FSL

If an FSL disk runs out of space there are different ways to address the issue

While the user is logged into the server:

  1. Open disk manager
  2. Add a drive letter to the user's VHDX
  3. Use a tool like WizTree to scan the disk and remove any large files
  4. Remove the dive letter you added! and have the user test again.
  5. In some instances the user will need to log out and log back in

From the File Server while the user is logged out:

  1. Make sure the user is logged out of the RDS
  2. Double click on the user's VHDX file on the file server
  3. Follow the steps on the previous section
  4. Make sure to detach the disk when you are done!

Add Space to the VHDX:

This should be avoided. If the disk gets full it is usually because of an underlying issue such as a wrong caching policy or too many logs.
drive space

If space must be added then it can be done so with diskpart. Some guides:


  1. How does one go about getting a VHD to mount on a Hitachi SAN? Regular Windows SMB works with no issues, this only happens when accessing a SAN disk


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