Hello Nick,
i updated the firmware to 5.6b3 and get an error on Midi.
My H8000 is audio connected via ADAT, gets Midi and workclock from a RME Fireface 800 connected to a Mac Pro.
In order to edit the patches in the H8000 i connected a PC via Firewire to the H8000FW also.
This works since years, but after updating i get an error "Midi Overload 1 occurred" if i recieving a patch to the PC while the Mac is sending Midi clock.
After the error occured on the screen the wordclock jumps out of syncing correctly.