Discovery must be done through an I/O group before you can use the addiscsistorageport command to establish sessions through that I/O group. You can run the addiscsistorageport command with a specific I/O group ID if you previously ran cluster-wide discovery.
Use the management GUI or the lsiscsistorageportcandidate command to view the I/O groups through which discovery was done. Use this information to correct the command, and then resubmit it.