Check. Can lines error, no comms

[Roadtoad]

Could anyone advise me on the error msg I've got using mes please. Says there's no communication between the engine ecu and the gearbox ecu (comfortmatic) and to check the can lines. I can't see a break anywhere in the connections. I suspect it is the gearbox module itself as it is the only module not showing up in a module scan ? I've tried to upload the image but can't find a way. Thanks