When threading the machine, make sure that the foot is up. This takes all the pressure off the tension discs and allows the thread to seat correctly. When you get to the needle, then put the foot down. Another thing you can try is 'flossing' between the tension discs. With the foot up, use a sturdy piece of thread, like top stitch or button hole and put it between the tension discs and floss.
When you were FMQing, did you break a needle? You might have a burr on your bobbin case. Run your finger around the case and see if there are any rough areas.