I accidentally hit “change” on the 3D printer, and now the filament needs to be reloaded, which I don’t have enough experience to do.
Also, I have been having problems with the prints not sticking to the plate. I cleaned with denatured alcohol.
In the back, the feeder has a little lever. Pull it up and that will disengage it. Simply slide the filament in by hand until it stops (don’t force it). Then simply reverse the process with the lever.
There was a little more to it. The setscrew in the knurled feeder had loosened, causing it to spin freely on the shaft. I couldn’t immediately find any usable Loctite (though we have solidified tubes aplenty), so I just removed the filament clamp and tightened the screw.
It might be worth disassembling the feeder mechanism and grinding a couple flat spots into the shaft the next time this happens. For now, the Ultimaker is printing happily.
Thanks for reporting the problem so it could be properly addressed.