Check the address included in the log for this error. If it is correct check for connectivity with the system and make sure a platform is running on the system. If is is incorrect you need to determine why the address was chosen. It is derived from the destination information contained in the original message. There is a two step mapping performed - mapping instance name to AE-Title and AE-Title to address. The original name may be incorrect, the mapping from name to AE-Title may have produced an unexpected AE-Title, or the mapping from the AE-Title to address may have produced an unexpected result.