Tracks won't load ProDJ Link

All of a sudden none of my tracks will load into my CDJs via ProDJ Link.
I've tried with RB5 and RB6.

I can't drag & drop them and the "Load" option from right-click menu is faded as well;

Also, there is network information as it does show the Mixer and both CDJs at the bottom of the screen;

What the hell..?