What line shows up when you click debug on the runtime error?

What do you mean "blew up"? I would be very hesitant to not know what happened to your previous database and just be blindly copy/pasting stuff into a new database, you could be pasting the problem in.

I had this happen to me just last week. It was a spelling error.
Check you have spelled your Form name correctly.

OK, so, some history, then. I had a working database until I split it and put the backend on winhost. After that, my device form won't open from the client form. My new device button doesn't work. The device form is not editable. The device form often opens to just the background color with no fields. The sale form opens with the detail form not showing, and several fields showing #name? or #type! errors. Any query that contains the client table is uneditable. I tried going back to a backup from before I split, and it does the same thing, so I doubt the split caused it. I dug throught it for about a week and gave up. The odd thing is, the exact same queries work in this database that I'm having the IsLoaded issue with. I imported the data from the old one with maketable queries and copied the queries and they work in the new one but not the old one. The mods are also direct copy/paste

Have you checked the link? Did you relink it after the split?  John

I did. In fact, even if I put it back together, it's budged, and previous backups that weren't split are budged. Data's all there, forms and queries are rubbish.