The bobbin thread is getting tangled when I sew

around the post? is the bobbin and bobbin case in the machine?

The motor locked up because the thread is tangled.
Solution:
Remove the tangled thread before continuing the operation.
Clean the bobbin case to remove the tangled thread.
After cleaning the bobbin case, insert the bobbin case properly.
If the needle is bent or broken, replace the needle.
Then, thread the upper thread properly, and continue the operation.

try changing the needle --make sure the needle is the right one
for the fabric being sewed
try a different thread
make sure the bobbin is not over filled
make sure the bobbin is turned the right way in the bobbin case
make sure the thread has not come off the thread take up lever

The motor locked up because the thread is tangled. Remove the tangled thread before continuing the operation.Clean the bobbin case to remove the tangled thread. After cleaning the bobbin case, insert the bobbin case properly. If the needle is bent or broken, replace the needle.Then, thread the upper thread properly, and continue the operation.
brother sewing machine

try changing the needle---flat side goes to the back side of the machine
also check the top tension
depending on the fabric your sewing on--the needle & thread have to work
with the fabric--example light fabric needs a different needle & thread than
a heavy fabric
check to see if the thread is coming off the thread take up lever when you
sew.

check the needle first.Bent or spurred needles will result in this action.

It could be that the bobbin is being put in upside down check to make sure that you do not need a bobbin with a magnet on one side. also make sure there is no thread tangled inside the bobbin housing it will cause the timing of the machine to be off and cause issues with your needle picking up the bobbin and thus cause a mess inside you bobbin housing

I had this same problem yesterday. I took apart the needle tension casing and now it doesn't get tangled or stop. The only thing is the bobbin is not sewing...it looks fine on the top, but the bottom is just loose loops.

To address my needle thread tangling (horribly) in the bobbin compartment, I rethreaded the bobbin. I cleaned the bobbin and the feeder feet, I changed the bobbin and the thread. I changed the tension on the needle thread and the bobbin thread. NO FIX! Then, I changed the needle - the problem was fixed instantly. I sewed awhile and then put the original needle back in. No problem. I think perhaps that the problem is being caused by the needle getting out of alignment somehow during sewing. If you are having the same issue, try it. It can't hurt!

This is a timing problem and will have to be repaired by authorized dealer.