>No other things I can try?
Well you can try what I've told you, unfortunately you did not give too much details on your tests, so here again:
Try the 3 cases.
Start with an empty rompath, add one set with 1 wrongly named rom file.
1st test case: keep the set as folder/file
2nd test case: use a zipped set
3rd test case: use a 7z set
The scan should find the wrongly named rom (inside the folder / inside the archives) and if fix options are enabled, it tries to fix it. According to your post, modifying causes the exit. So try all 3 cases. Which one fails?
Instead of having one wrongly named file inside the archive/folder, you can also add a random file to it, which should appear as unneeded and fixing them would also cause a modification step. Let's see if that works.
You can post screenshots of the scanner windows where it lists (when fixing is off) your test case result, so I can have a look if that setup is ok already.
>Is there a way you can make a Mac version?
As the readme states, new scanner/rebuilder will get open source if they are done.
So you can try to get it compiled on a Mac.