"Load Frame Sequence" loads empty frame if attempting to load an image with no numbers in the name

Visionaire Studio v4.2
Steps:
1. Pick empty (or not I guess) character animation
2. Click "Load frame sequence" and select image file with no numbers in the name, e.g. "jonny.png".
Results:
Empty frame is added to animation
Expected Results:
Image should be loaded as a frame. If for some magical technical reasons it can't be done, a proper warning asking for number in the filename should be shown.