I checked  before posting.

in the end seems like it was some glitch in the system.

I changed a different value in the GUI ,saved and then reverted and tried setting the above setting and works OK.

the connection does not  complete successfully.

no messages arrive after adding IP to AllowedIPAddresses list 

i tried adding all the sending IP addresses (including the ones i want to filter out) just to see if for some reason me touching  the setting caused the problem, and it that works ok.

when i remove one of the sending IP addresses from the list and receive a message from a IP not in the list. i see "Rejected connection attempt on port ...."  in the log and then  the above error.

Thanks

Hi

What's CountedXML ? does it mean that the length is known?