I recently ran into a small issue applying a patch to one of my lab’s vCenter Servers. Specifically, attempts to patch the vCenter Server ran into the error, Exception occurred in install precheck phase.
Despite rebooting the vCenter Server Appliance, I was unable to regain access to the vCenter Server Appliance UI and was essentially trapped in the above loop.
The fix for me was fairly quick via the below steps.
1. Firstly, SSH to the vCenter Server Appliance.
2. Enter BASH via the below command:
3. Clear the update state by removing the below file.
4. At this point I was able to regain access to the UI, however, retrying the update again resulted in the same error (requiring me to run through steps 1-3 once more). After manually downloading the vCenter Server Appliance patch, attaching the ISO to the vCenter Server Appliance VM, I was able to install the update via the Check CD-ROM option.
5. Finally, the update was successful.