EXM448 Fatal Error

We have projects that reported fatal error of EXM448 based on two LEDs on it's circuit bord. That means the green LED is flashing at 5 Hz frequency.
I try to know the error code according to the manual, but I can't find block "@CSPRO", it was not configured before. I tried to find some online diagnostic message from hardward configureation, EXM448 looked OK, FM458 had some messages in the buffer, but it looked have no releationship with EXM448.
Could you please tell me want kind of reasons can cause this "fatal error"?
What should we do when we have this error?

• First you should check the EXM448 is included in the hardware configuration.
• If you have two EXM in the hardware configuration, both must be pluged in. It's not possible to leave one out for commisioning.
• If you have no central communication block (like @CSPRO) the board is not initialised and will not work. I think the FM458 ignores the EXM in this case.