Knowledge Base

Problem

CatWalk XT refuses to open an experiment file and displays an error such as 'This experiment was made with a previous version of CatWalk XT.' The experiment data itself is intact but the software cannot read it.

Details

Affects any CatWalk XT version when the version.dat file inside the experiment folder becomes corrupted or is misnamed (e.g., version91.dat instead of version.dat). Commonly reported after software updates or file restores from backup.

Solution

1. Close CatWalk XT completely.
2. In Windows File Explorer, navigate to the experiment folder (default: C:\Users\Public\Documents\Noldus\CatWalk XT\Experiments\<experiment name>).
3. Locate the version.dat file. If it has a version number in the filename (e.g., version91.dat), note that it must be renamed.
4. Obtain a clean version.dat file from a working experiment created with the SAME CatWalk XT version, or request one from Noldus Support.
5. Rename any incorrectly named file (e.g., version91.dat → version.dat).
6. Rename the existing corrupt file in the problem experiment folder to version.dat.old as a backup.
7. Paste the clean version.dat into the problem experiment folder, overwriting (or alongside the renamed backup).
8. Reopen CatWalk XT and open the experiment – it should load normally.