Audio unit causes GarageBand to crash, now it is in iPadOS 26.2.1

bad audio unit causes garageband to crash - Having now updated to ipadOS 26.2.1 it seems there is an issue whereby a ‘bad’ or out of date Audio Unit, causes GB to crash before I can get in the song and delete the AU.

Obviously this is a problem - if I cannot access the song inside GB I cannot delete the bad Audio Unit. This is existential to my use of GarageBand, the app which is my sole reason for having an iPad Pro M1.

ideas are welcome. I tried duplicating the song, but no different. Worked in OS 17 and 18.