Hairless midi crash

I'm getting this error, I did see a post with this before but the fix didn't work

got a status byte when we were expecting 1 more data bytes, sending possibly incomplete MIDI message 0x90

unsure how to tag the code so here's a link

I'm using the adruino uno with 2 buttons in currently.

I'm trying to make a midi controller

unsure how to tag the code

Then please read this:-
How to use this forum

Now post the code that is giving you an error. Also please state what baud rate you have set hairless to.