This issue preceded the previous post, so I may not have all the details, but it did occur while attempting to set up a similar modulation matrix.
The symptoms were that sound would still play if MIDI notes were triggered on the keyboard, however the UI was completely frozen and non-responsive, and would not switch pages.
I looked to see if there were a way to sysex dump logs or something but I couldn't find it and eventually just restarted the machine.