It seems that revision 252 ("Change to savefile format to allow for some vg music formats to be included in quest files in future versions."😉 causes ZC to break when loading NeoFirst - in particular, when it's loading NeoFirst's MIDIs.
Quest file format broken?!
was fixed/reverted with build 254 i thought.
Seems I made a mistake somewhere ... yeah. DD fixed it. Sorry for the disturbances caused.
Ah, right... seems I just have to restore a quest file backup.