The error message is in Norwegian but is says something like "The chosen airline could not process this registration". That's printed once, and then for both of the claims it says "You cannot register points for this route".

There is another confusion. SAS asks for a 13 digit ticket number and the booking confirmation and KLM app give *one* number ending in 0. But the boarding pass for the return changed the last digit to 1. So I used that. Now I tried again with the original number ending in '0'. Same result. As for booking class for the rebooked: I really don't know, as mentioned the booking says L but the boarding pass says M, so did the new boarding pass.

I now tried to do only UIO-AMS, still same problem. I think I'll wait some days and try again.