Roland MC 101 Note Empty in sequencer mode

[jungle]

Normally I can be in NOTE mode then press a note and when I switch to SEQ I can then enter that note into the sequencer.

But sometimes, when I switch to SEQ and press a pad it says "Note Empty"...

And I don't know what I did to get into this mode or how to turn it off. I tried looking through the manual and googling it but nothing turned up...

[trackedchanges]

Is this happening in a Drum track or a Tone track?