I have a problem with my midi keyboard, that does not appear in the list of selectable inputs... or rather, after several attempts it appeared once, so I selected it but despite this it did not play any sound. Then I tried to select it as output and at that point LMMS crashed.
Later I tried again but the keyboard no longer appears in the list... or rather, after several attempts it appears again, I select it but I cannot hear anything.
What should I do?

EDIT - PROBLEM SOLVED !
I solved it by going to "settings" - "midi" and selecting my keyboard from there... ...and yet this was the first thing I did, but at that time it was not present in the list... mysteries of faith