Knowledge Base

Problem

EthoVision displays an error message when a user tries to open an existing experiment (.eap or behavior) file that is stored on the local computer, preventing access to previously acquired data.

Details

Affects EthoVision XT experiments stored locally. Symptoms: an error dialog appears immediately when double-clicking the file or using File > Open; the file was last used on the same computer without issue. Can occur after a software crash, abrupt shutdown, Windows update, or if a .vtl lock file is present. May also occur if the experiment file is on a network share with permission issues.

Solution

1. **Check for a .vtl lock file:** Navigate to the experiment folder in Windows Explorer and look for a file with the same name as your experiment but with a `.vtl` extension. If found, close EthoVision completely, delete the `.vtl` file, and try reopening the experiment. (See also: 'EthoVision .vtl Lock File Found in Experiment Folder' KB article.)
2. **Check file/folder permissions:** Right-click the experiment folder > Properties > Security and confirm your Windows user account has Full Control or at least Read/Write access.
3. **Move the file locally:** If the file is on a network drive, copy it to a local folder (e.g., C:\Users\Public\Documents) and try opening it from there.
4. **Try opening from within EthoVision:** Launch EthoVision first, then use File > Open to navigate to the experiment file rather than double-clicking it in Explorer.
5. **Check free disk space:** Ensure the drive where EthoVision stores temporary files has adequate free space (several GB recommended).
6. If none of the above resolve the issue, contact Noldus Support and provide the exact error message text and a description of recent events (crashes, shutdowns, updates) that may have preceded the problem.