My CatWalk XT experiment will not open as it reports that it was made with a previous (or newer) version of the software, but the same version was used.

This issue results in the inability to open a CatWalk XT experiment, with a warning message that it was made with a newer version of the software, but the same version was previously used. It may also report an older version was used, but fail to convert the experiment to the new version. The error message may appear as shown:  

Solution: the “version.dat” file in your experiment is corrupt and needs to be replaced.  

This problem is easily solved, since the version.dat file is present in every experiment and contains no other experiment data.

1. Locate another experiment that is working. If you don't have any other experiments, open CatWalk XT and click “Create a new experiment” and create a dummy blank experiment.
2. Open that experiment’s folder location in the Windows File Explorer (C:\Users\Public\Documents\Noldus\CatWalk XT\Experiments by default)
3. In that folder, right-click on the file “version.dat” and select “Copy”.  
4. Open the problematic experiment’s folder and right-click on the “version.dat” file, select “Rename” and rename the file “version.dat.old” (it will warn that it may be unusable, so just click “Ok”). 
5. Then, right-click in the blank space of the experiment’s folder and select “Paste” to paste the “version.dat” file from the working/new experiment.  

After doing so, close the File Explorer and CatWalk XT (if open), re-open CatWalk XT and see if the issue is resolved for your problematic experiment.