I've learned to hit the save button regularly, so I can kill it and still have everything. After a restart of LBC, I of course dragged over 4 file links with no problem. The overall problem seems to be that adding 10 or 12 things at a time drives it nuts. So when you try it again later its fine. I'm in the phase of trying to create my LB for the first time, so I'm doing a lot of additions. I think the adds will be less now. Every time I've crashed it, I try the exact last thing again, and it works. It needs the whole sequence to foul it up.
If you ever have a version of LBC that has extra logging or diagnostics, I be happy to run it.
They don't look very informative but I attached a couple of .wer.
Side note: tell you what would be a lot less frustration, when I add an item, be it menu or new command, it would be really nice of the "new command" or "new menu" was selected so you could just start typing the real name.