Just take the footplate off
(the instructions will be in your manual)
and remove the fluff.
Put the footplate back and carry on.........
I know what caused this, too much machining felt
This blog is for Hints and Tips that work for me in the crafts I do from Fabric to Food! They may work for you. It may look as if I go the long way round to achieve the end so........if you know a simpler way please feel free to let me know.