This is the usual cause. When opening the editor, it looks for the last-opened patch. If this patch has been moved into a different folder then it can’t find it and crashes.
Work out what the last patch you opened was and move it back to the folder it was in them launch the editor.
I’ve emailed @Andras Szalay to ask if the editor can be updated to make it just load an INIT patch of it can’t find the last-loaded patch.
If you have no joy with that method then uninstall the editor and use App Cleaner by FreeMacSoft to remove the residual files and then reinstall the editor. You’re not the first person who’s done this this weekend.
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No need to reinstall. There is an easy fix of the problem:
Open the following file:
c:\Users\YOUR USER\AppData\Local\FutureImpactEditor\settings.ini
(replace YOUR USER by your USER NAME)
and delete the lastfile entry
[midi]
indev=off
inBdev=off
outdev=off
[gui]
guiscale=1.103092783505155
[program]
lastfile=D:\...........\Future Impact 1\Patches\Patches All\02\96-P0374_ta_Zach_Proton_Sounds_15_4Saws.pr3