Midi Issue

[Pete Morten]

Hi all.

I'm trying to set up a session so I can send Midi Control Programme Changes
to my Rocktron Guitar Preamp Rack Unit for live applications.

When I click with the pencil to add a programme change I keep getting this dialogue box (see attached)

As I'm not overly savvy with Midi, could anyone the tell me how to actually correct this?.

Last year I set up a previous session doing the exact the same thing with no issue?. A bit confused as to why it's doing this now?.

Many thanks for any help offered

Best
Pete