Try rethreading machine
top thread tension to tight
needle damaged
thread & needle may not be compatable--here's how to check
Cut 6-8 inch piece of thread of the spool you are going to use for your project
Take the needle you are going to use for the project
& insert the thread thru the eye of the needle
& lift one end of the thread to a 45 degree angle
& if the needle is the right size for the thread it will slide down the thread
But if the needle hangs on the thread you need one size larger needle for the thread