Troubleshooting issues with container locked or in use

Important

An upcoming change to Windows, included in the April 2026 Windows Server update, the default Kerberos encryption type is changing from RC4 to AES-SHA1.

File shares hosting FSLogix containers that aren't upgraded to AES-SHA1 might have access issues after this change is applied. To avoid disruption, complete the upgrade to AES-SHA1 before installing the update.

Customers who have already upgraded to AES-SHA1 aren't affected.

For more information, see the FSLogix blog: Action required: Windows Kerberos hardening (RC4) may affect FSLogix profiles on SMB storage.

Clean up invalid sessions

In some configurations, user sessions are signed out and a process or application prevents a proper sign out operation. This can leave artifacts on the file system or registry. During a sign in operation, these artifacts prevent the container from detaching and new sign ins are blocked. This can also occur if the session is terminated abruptly.

Recommendations

  • There could be an operational issue in the environment. Prioritize any environmental or system issues that help solve the root cause versus the symptom.
  • Setting: Enable CleanupInvalidSessions

Concurrent or multiple connections to a single container

The default configuration of FSLogix prohibits a user from using their container in more than a single connection. When this situation is paired with the PreventLogonWithFailure setting, users can't sign in and receive an error from the FSLogix shell (frxshell.exe). FSLogix maintains an exclusive lock on the user's container while they're connected to a virtual machine and concurrent connections is disabled. Concurrent or multiple connections are supported in some configurations.

Recommendation