Knowledge Base

Problem

EthoVision displays a 'lock error' when a user attempts to open or export data from an experiment, preventing access to the project.

Details

The lock error indicates that the experiment was not closed properly during the previous session (e.g., due to a crash, forced shutdown, or improper exit). EthoVision places a lock on the project to prevent simultaneous access; if the lock was not released on exit, it persists on the next open attempt. Seen across multiple EthoVision XT versions.

Solution

1. When the lock error dialog appears, click 'Close' (or the equivalent dismiss button) rather than canceling or force-quitting EthoVision.
2. After dismissing the dialog, re-select the experiment from the recent files list or via File > Open and attempt to open it again.
3. If the error persists, check the experiment folder for a .vtl lock file. If EthoVision is fully closed and no other user is accessing the experiment, delete the .vtl file and then reopen the experiment.
4. Ensure that only one instance of EthoVision is accessing the experiment at a time, and that the experiment is not stored on a network drive being accessed by multiple users simultaneously.
5. If data export was interrupted, attempt the export again after successfully reopening the experiment.