Sometimes the thread causes the problems. Use a new spool or different brand. It's worth it to use better brands even for thread.
I have a friend who had her machine in to be repaired twice this fall and finally she changed the thread and voila all fixed!!

The last time this happened to me, I tried everything. Lower tention, upper tention, re-thread the machine ... yadda, yadda, yadda. Then I changed my needle and Walla! Still don't know exactly what I did to fix it, but it worked.

Well, if it is the bottom of your material, that means it is the top of the machine, if it is the top, it is the bobbin.
But if it is both? Well, you need to take your machine apart
clean it well, oil it and put back together. If that doesn't work
you may need to get it serviced. Good Luck.

And change your needle, that is important.

I'm with Tina and jdeery-Change your needle! Sometimes we push those little ones too far. Your problem looked like like my problem and once I changed my needle I had no problem! Just use a good quality needle.

please take a few minutes and try this..1 get a new bobbin and rewindat fullest speed...2. put in a new needle...3. try a few drops of oil at the base of your bobbin..remove your plate and get rid of dust/lint..4. check your tension and 5. rethread your top thread..perhaps even changing to another thread...you should then be like brand new...good luck

Make sure you are not using hand quilting thread in the matchine. It is coated to make it stronger and it really gums up the machine. I learned this the hard way :-)

Rethread and check tensions. Looks like a tension problem.

Just had the same problem, driving me nuts, it was also the thread I had in the bobbin. For some reason it just didn't like it anymore. These machines are more fussy l than my kids.

UGH

I was having a similar problem so had my DH look at it. He used to sell sewing machines yrs. ago so he knows more about the machanics than I do. He removed the bobbin and shuttle. There was so much dust and lint under the shuttle I was dumb struck. He cleaned it out and adjusted the bottom tension and now it works fine. Hope this helps.:-)