I just bought some Jup-8V presets from Musicrow (which I'm sort of regretting). Most load fine, and probably if I still had Jup-8V3 it would have worked, but it's not loading into Jup-8V4 for I think probably similar reasons?
There must be a way to migrate patches from older incarnations to V4 (obviously Arturia have done so?)
Thanks to looking in the General Forum, I checked the "Include Legacy Sounds" option in Analog Lab V and I find the Musicrow presets have magically appeared (so they can't be loaded in to the new Jup-8V because of preset incompatibility).
I'll add my voice to those requesting some migration tool. The Jupiter front panel settings should be migratable at least?!
Edit: Just to clarify how I got some old preset bank to import:
1. Change the extension to .jup4e - even though it's not a V4 bank!
2. Choose import... from the Jup-V4 menu and select the bank.
3. Jup-V4 says the bank imported successfully, but no bank actually appears under My Sound Banks in the preset browser.
4. Switch to Analog Lab V and activate "Include Legacy Sounds".
5. Browse the sound banks in Analog Lab and you'll find the imported bank.