“A problem occurred while getting data from the source vCenter Server” error when upgrading to vCenter Server Appliance 6.7 U1

Seeing that vSphere 6.7U1 was recently released, I decided to upgrade my VCSA 6.5 appliance to 6.7U1. Downloaded the installer ISO, extracted the ISO to a temp folder then ran the installer wizard.

I then launched the installer, select the “upgrade” option and put in the details of my existing vCenter credentials and ESXi host credentials hosting the existing appliance. Upon clicking on next, I was presented with error “A problem occurred while getting data from the source vCenter Server” and the option to download the installer log.

After looking through the installer log for errors, the following line kept repeating itself a few times in the logs:

debug: Failed to get url of file in guest vm:ServerFaultCode: Failed to authenticate with the guest operating system using the supplied credentials.

I was sure that I entered the correct credentials as I could login to the VCSA management GUI with root credentials. However, looking at the Administration section, I noticed that the password was set to expire in 1 Apr 1970 which indicates that the root password had already expired.

Changing the root password from the GUI didn’t work either and it would present the error “Permission Denied. Set the maximum number of days when the password will expire. Administrator configuration updated successfully.”

The fix is to login to the VCSA via SSH, enter the “shell” then use the “passwd” command to change the password.

After doing this, I was then able to continue onto the next section of the VCSA 6.7U1 installer.

Hope this helps anybody facing the same issue.