Hi,
This error points to a wrong braking behaviour of your machine. Make sure you test your SRK board on a similar press to confirm that it is okay though fault can also be caused by any other board on top(1st) cabinet layer. The RER2 is the motherboard on which the REKs/ SRK plug into. Hope you have basically rebooted the machine and check that fuses are not blown too.
Good luck.