Anyone know of a good way to downgrade UDTs & tags from 8.1 to 8.0?
(don’t worry about the “why?”) 
The 8.1 export structure changed the UDT parameters and it’s screwing things up. 8.1 now throws the datatype in and 8.0 doesn’t handle it well.
I can manually adjust the export file to fix the handful of UDT’s, but the export of the instances also have the extra bits in there.
Nobody answered you
Ignition’s backup, project, and tag files have never been “forward” compatible. That is, newer Ignition supports importing most older versions (“backward compatible”), but not vice versa. Anyone who tries to do so is on their own, and is unlikely to succeed on anything but the most trivial examples.
Yeah, I wasn’t expecting it to work out of the box, but was hoping someone had a script or a technique that would work for going backwards. We still have clients who are hanging onto 8.0 that haven’t made the slight jump to 8.1, and that hampers our development & deployments.
And when someone mistakenly does the import, Ignition seems to accept it, but there’s a few non-obvious errors in the structure that messes it up. I had a newer guy do a bunch of imports on a live system and then was stymied for a bit on why stuff was broken. The slight errors weren’t obvious.
If I had a free moment or two, I’d see if we can export to a file, then run a script to “fix up” the structure and then ready it for import.