If you are experiencing this issue try the following:1) Remove the binding post screws attaching the 9-pin d sub connector on the rear panel of Control|24 marked "I/O". That port is only used in the factory for initial setup and is securely mounted on the inside.2) If you are using a shielded ethernet cable, such as the one supplied with Control|24, remove the metal shield from around the RJ-45 connection on the unit end of the cable. It should pull off easily and is not required for safe operation.