The E50 error code on a Brother embroidery machine typically indicates that there is an issue with the motor encoder. The motor encoder is responsible for ensuring that the machine’s needle is in the correct position while embroidering. When this component fails, the machine is unable to accurately determine the needle position, resulting in the E50 error.

To fix the E50 error, you can try the following steps:

1. Power off the machine and unplug it from the power source.
2. Wait for a few minutes before plugging it back in and powering it on.
3. If the error persists, check the connections of the motor encoder to make sure they are properly seated and not loose.
4. If the connections are fine, it may be necessary to replace the motor encoder. This should be done by a trained technician.

If you are not comfortable troubleshooting or repairing the machine yourself, it is recommended that you take it to a Brother authorized service center for repairs. They will have the expertise and equipment necessary to diagnose and fix the issue.