solved error of the detect keyboard midi

My system ubuntu 20.04
keyboard midi - Casiotone st200

I was having the same error as many about detecting the midi keyboard, I did several tests and nothing, I realized that the keyboard was detected on the USB, I managed to run with the VMPK software, but in the musescore nothing

I followed all the procedures, connected the keyboard before starting the musescore, the midi connector was active, and the "N" was pressed.

In properties the keyboard was detected, but nothing.

Solution:

After a long time, I thought of something, what if the USB peripheral of the computer keyboard is interfering with the USB peripheral of the midi keyboard?

So I disconnected the computer keyboard, and I connected the midi keyboard, and it worked!

I reported here because many may have the same problem