Core issue
The Standby console disabled error message indicates that you have connected the console cable to the standby supervisor and not the active supervisor.
There is no console connection to the standby supervisor. The console is always disabled on the standby supervisor.
In some scenarios, when you run Cisco IOS Software Release 12.2(18)SXF2 and Cisco IOS Software Release 12.2(18)SXF3, after console timeout, standby supervisor access is possible. But, this problem is not observed in Cisco IOS Software Release 12.2(18)SXE4. This problem is identified in Cisco bug ID CSCse53090.
Resolution
In order to remove this console message, change the console cable to the active supervisor and then you are able to access the switch.
If the symptoms match Cisco bug ID CSCse53090, then the workaround is to configure the exec-timeout 0 0 command in order to set the interval that the EXEC command interpreter waits for until user input is detected.