Help! Plugin Issue

Just installed an external HD drive. Thought I would copy all my music related files across to it and free up space on the primary HD (it's an iMac).

Didn't realise that my plugin folders were in the folder I moved. No problem (I thought), I'll point the MPC software at the new folders and re-scan. Did this and all looked okay.

Until I tried to use one of the plugins (Beat Machine). The MPC software appeared to record the MIDI notes fine, and they played in the plugin during recording, but on playback there is nothing. I also notice that the preset pulldown just has the current preset but says 'no choices' when I try and pull it down.

Uh oh....seems Akai have deemed it fit to hard-code it to need plugins on the primary HD. I therefore copied the plugin folders back to the original location, then re-scanned for them. Everything fine yes?

But no. I still have the same issue, but whats weirder is the piano keyboard image on the side of the MIDI sequence is playing a different note (one down) from the one recorded, and displaying in the MIDI piano roll.

Am at the end of my tether with this. Why is this so difficult? Stuff like this kills my workflow and makes me question if I should have invested so much time on Akai products

Ok now figured that the problem with MIDI playing the incorrect note only manifests itself in my current project. If I start a new project, it seems to be okay, although the presets list is still missing.

What would cause the MIDI capture to play back at a note lower than that recorded? If I manually move all notes up by 1, it seems to play although I don't now have confidence in my project file

OK, happening on all MIDI now. In fact, if I play a sequence on MIDI (say a key group) and then switch to a different sequence and back again, it plays a note lower every time - progressively getting deeper and deeper, despite the piano roll staying the same.

In fact, if I play a sequence on the keyboard it sounds fine when recording, but then when taking my hands off the keyboard and letting the loop progress it immediately plays one note deeper

My guess at the moment is some sort of corrupt project, but this is some super weird behaviour from the MPC software