An icon appears beneath the window after recording, but when clicking on this the "Quick Time cannot open" message appears. Same thing happens if I select 'Finder' and try from there. I have tried different formats but still no success.
I checked the description of the application, and it appears it supports MP4 exporting. The MP4 file format is recognized by QuickTime and should be seen no matter what.
Try installing VLC Media Player and open the file. If the MP4 has been encoded with an unknown codec, then VLC will try to open it.