Which Scarlett model and generation do you have?
There is a discussion here
about the Scarlett 3rd Gen interfaces having problems with “Windows WDM-KS”. The recommended workaround is to use WASAPI, disable “Play back my audio” in jammr's sound settings, and enable direct monitoring on the soundcard.
I test jammr with a Focusrite Scarlett 2i4 1st Gen and it works with the “Windows WDM-KS” audio system. I have ordered a Scarlett Solo 3rd Gen and will work on “Windows WDM-KS” support for lower latency.