You can review the support bundle log messages to identify the upgrade problem.
You can also perform any of the following debugging tasks.
- Log in to the NSX Manager CLI as root user and navigate to the upgrade coordinator log files /var/log/upgrade-coordinator/upgrade-coordinator.log.
- Navigate to the system log files /var/log/syslog or API log files /var/log/proton/nsxapi.log.
- Configure a remote logging server and send log messages for troubleshooting. See NSX-T Data Center Administration Guide.
Note: If you are unable to troubleshoot the failure and want to revert to the previous working version of NSX-T Data Center, contact VMware support.