I have a ESXi v6.5 running on IBM M2. The ESXi is managed by vCenter V6.7. I tried to patch the ESXi with Update Manager. Update manager always fails with error, The host returns esxupdate error codes: -1. Check the Update Manager log files and esxupdate log files for more details.
The update manager and vCenter are installed on Windows 2012 Server. Please advise how I can proceed to troubleshoot and fix the issue.
Have you checked the Update Manager log files and esxupdate log files for more details?
If not, take a look at them:
Windows 2008 and later operating systems:
C:\ProgramData\VMware\VMware Update Manager\Logs\
ESXi (patch and update installation logs):
Also take a look at KB below. It describes your issue.