Switch it off. Remove the bobbin and bobbin case, give it a good cleaning.
Could be just lint. Then rethread the top also. If you still get that message
then your machine might need to go to the shop.
My machine was sewing in reverse the other day. I stopped and cleaned it
then it was fine. Weird but it happens.
Hope yours is an easy fix.
Edit: Try a new needle. Maybe it's bent and hitting something.