I've never had a problem with Kemper since I have make update to the last 2.3 firmware few days ago .
Let's disregard the problems with the browser mode and that it can sometimes lose the sound of a given amplifier and when you move the browser button- each sound is virtually the same.
This problem is solved with Kemper shut-down and re-ignition .
But today I survived the greatest stress because of the following .
Suddenly, OUTPUT and INPUT buttons are discoloured, they have stopped working. But not only that, they were blocked like the other buttons A, B , C , D and X.
When I started Maintenance mode I ran a test where it told me the buttons for Delay and X do not work , and also the above mentioned buttons didn't work .
I already thought that LED lights or something about it died in Kemper... 
Then I committed fully flashing from the above Maintenance mod and returning to the 2.2.1 version and I reload all profiles .
Fortunately, all is well, the colours are back to the buttons, as it should be.
I write this just to draw attention to this bug to fix it, just not to experience stress as I am. 
All the best !
Borjan