How do I solve this Tamper lockout?

new install accenta 8SP399A. Constantly gives tamper lockout though wiring is correct. Message reads on top line 1-8 followed by TP, and the bottom line is 8 zero'es followed by FO.
I can get into engineer mode and change things but on exit lockout still exists. Comms not used so wonder if terminals should be linked out in some way though the book doesn't mention that.
I am looking stupid here so hope you can help.
Ken Wolfenden