So I just came home from the post office with my new ACA 500 Plus.
I was currently using the ACA 500 (Original ACA 500) and fully unlocked ACA 1221. My boot CF card has Classic Workbench installed. So I unplugged ACA 500 + ACA 1221 and installed the new ACA 500 Plus in my A500 Plus (without the ACA 1221). I put the same CF card with Classic workbench into the ACA 500 Plus.
I get to the ACA 500 Plus boot meny and hit F1. Workbench starts to boot but after a few moments I get this error message: C:StackAttack Program failed (error #80000004 Wait for disk activity to finish. So it seems to get stuck here. This works just fine with the ACA 500 + ACA 1221 combo. I also made sure to not use the ACA 1221 stuff in the boot sequence. I also tried another CF card with Classic Workbench and got the same error message.
What could be causing this?