Try reloading the Executive from C-Max (Controller Utilities, Reload Controller Executive). You will have to reload your C-Max program into it when done.
If that does not work, and the red comms light is on even when the Comms A and B wires are not connected, it's a problem with the Leopard itself. Try another comms chip without connecting it to the modules. If the comms light is still illuminated without being connected to the modules, it will have to com in for repair.
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