Battery grip , one side not working

The right hand side of the 'add on' battery grip for 5dmk2 does not communicate with the camera , all batts I have work fine in the left side ?

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 1
crwdns2934285:0crwdne2934285:0