I powered cycle the crate and started another run. I checked the connection in the SFI, the CPU was well seated, scaler was not as well seated so I pushed it in more but I doubt that is the reason of the problem. Not sure what is the problem either, and hard to troubleshoot since it takes time to generate the error after power cycling.
I guess you could try to drop half of the modules and proceed by doing a dichotomy if it is a bad module.
I think the DAQ group has a board to look at the fastbus bus we could check with them on Monday to see what is going on there when it gets stuck.
Could also check the voltages are fine.
Can you estimate after how long the problem appears ? Might be a module heating up.