Why does it keep doing this?

It tangles up like this when I begin to sew and stops up the machine. This has happened once before and I figured out why, but that isn’t seeming to be the problem this time. I’m stumped.. I use a Brother sewing machine

It tangles up like this when I begin to sew and stops up the machine. This has happened once before and I figured out why, but that isn’t seeming to be the problem this time. I’m stumped.. I use a Brother sewing machine