The E2 error on a Brother embroidery machine typically indicates a problem with the thread. Here are some steps you can take to fix the issue:

1. Check the threading of the machine. Make sure the thread is properly threaded through all of the guides and tension discs.
2. Check the tension of the thread. Make sure the thread is not too loose or too tight. Adjust the tension as needed.
3. Check the bobbin. Make sure the bobbin is properly inserted and wound with thread.
4. Check the needle. Make sure the needle is not bent, dull, or damaged. Replace the needle if necessary.
5. Check the embroidery design. Make sure the design is not too dense or complex for the machine to handle. If the design is too dense or complex, it may need to be simplified or broken into smaller sections.
6. Clean the machine. Clean the machine and the area around the bobbin case to remove any debris or lint that may be causing the error.

If these steps do not solve the E2 error, it may indicate a more serious problem with the machine’s internal components. In this case, it is best to contact a qualified technician or the manufacturer for assistance.