Ben there, done that! I'm sure others will pipe in with the same message. :-) Also, welcome to the Board!
This happened to me because I didn't thread the machine correctly. This, on a machine I've had for twenty years! Huh? They were right -- rethread your machine and try again. Also, it may sound obvious, make sure your presser foot is down.
I think what happened with my machine is I left it in the garage/three season room (I was sewing out there) and it was just a bit too damp. Instead of being able to quickly thread the machine, I really had to make sure I tugged the thread into the tension area. That was the problem.
Good luck!