The logentry "Message size *** exceeds the maximum size 67108864 bytes. Message ignored." Doesn't give source info, would like to know the IP for instance or any other info that lets me find it

All of a sudden (since a trunk upgrade), I'm getting warning messages "Message size *** exceeds the maximum size 67108864 bytes. Message ignored."
It's in the file src/libs/zbxcomms/comms.c

I would like to know the culprit.
I have no idea now.
The IP might help