In attempting to copy and rejig a complex Hype project, I thought I’d just drag resource files into a pretty full Hype resources pane (needs scrolling) from Finder (rather than using the + button). Big mistake! this has led to some stuff being wrongly inserted into inappropriate groups (like an mp3 sound into a png group). I thought, what the hell, just drag out the erroneous placements and drop them outside of any group. But I can’t do it it – they won’t move. If this were a small project, I’d start again with the plus button, but that would be a lot of work. Is that my only option, or is there some way of moving files in the resources pane by drag and drop?
The naming indicates what group it will go into, so even if you remove something, if it were re-added it would go into the same group.
My recommendation would be to use the 'File > Revert To > Browse All Versions…' (or otherwise a backup) if you want to get into a prior state and haven't otherwise made lots of other changes yet.