Registration failed. Do one of the following:

• Press and hold down (Power On/Off) to turn off the machine. Wait a few seconds, and then turn it on again.
  Perform the color registration again.
  > Click here to see how to perform the color registration.
• Install a new belt unit.
  > Click here to see how to replace the belt unit.

If the issue continues, contact your local Brother dealer or contact Brother Customer Service from the "Contact Us" section.