Solved: REAPER does not receive midi!!!

[Slowfox]

Hi,
I run REAPER v5.980/64 and I have a problem with setting up a midi controller!

I followed every step exactly as told in the REAPER tutorial but it does´nt work.

I did activate the midi controller as an input device. Did check the use as controller field.
Then I tried to assign a key of the controller to an action parameter, but reaper does´nt read any midi data.
I checked if midi data is received in the computer with a midi monitor. Everything works fine, only REAPER does´nt read the midi data at all.

What can I do?

Thanks for help here…