Hope it's all straightened up today!
I forgot to mention the second thing I always check - the size of the needle. If the needle is too large for the thread, the thread doesn't receive enough friction as the needle ascends to form a loop that the hook can catch. Skipped stitch.
So if you're using a 50 or 60 wt thread but you've got the size 14 jeans needle in the machine from your last project, the jeans part is okay because it's a sharp needle, but the size of the needle is too large for the diameter of the thread. Go with a 10 or 11 or 12 and see if that doesn't help.