Customer cannot execute command interface stack-port command under system-view.
1. Request customer share diagnostic-information and check below information:
- display version
- display device
2. By version and device information, stack command should be able to execute.
3. Request customer to share all logs in logfiles.
4. Checked again the logs, show that previously stack is working fine.
5. Probably someone disable stack used command "Undo stack enable"
Customer did reset factory-configuration command and then reconfigure again for stack.
Need to check previous action done by customer. In this case, previously stack was working fine.