I don't have the same machine as yours I have Brother machines but work in a repair shop and sounds like your machine may be out of time. If your bobbin case may not be in right also. Remove it and put it back in but make sure it is correct. Your book should show you or explain. Call a repair shop near you and ask, they may tell you it could be out of time and needs to be seen. Good Luck hope this helps
I hope someone with your machine can help you. I'd suggest calling your dealer and explaining the problem, it may be something simple they can help you with over the phone. Best of luck, it's tough when our machines don't work right! Hugs, Marji
Something similar happen to my PFAFF Creative 2.0.
After trying every thing I decided to have a look at my setting in the machine and I switched off
"cut jump stitches" and magicly it worked !
Hope it helps !