MB300 bus error

The system is really small, only one combiened AS+CS and one AC450. The old 800xA was V4.1 now it is V6.0.3. With the new system I get a bus error freqently which I don't have seen in the old system. It comes and go with the same time stamp.

I add the event details as screenshot. The event comes from the controllers node number. All works fine so I would guess that there in not really an error.

Any idea what happens or how I could get rid of this annoying message?

/Erik