musescore preferences doesnt save

Hello all,

I'm using windows 10 and the latest version of musescore.

I'm trying to use a midi keyboard to write notes in the software, and so i'm trying to change the the preferences>io: changing midi input to 'MMsystems,MPKmini2', then changing device to 'microsoft sound mapper - output', and changing midi output to 'MMsystems,MPKmini2',
Then i press apply, then ok. Then i restart musescore and press 'n' and then 5, so that its in note mode, and still no respond from the midi although it is on. Then when i go to look at the preferences i see that they are wiped out. They even wipe out if i dont restart the program, and just close the preferences tab after pressing ok.

Any way to fix this?
Thanks a lot!