I tried to login to VCenter Appliance Web interface after very long time, and notice unable to login on appliance and below error.

The quick fix for the error is log in to Appliance Console/SSH and goes to Shell and run the passwd command and provide the new password, then repeat the new password. Once password updated. You can login to web console.

In this article I will show how to upgrade VMware ESXi version using offline-Bundle.

• Download the VMware Esxi Offline Bundle
• Upload the Offline-Bundle to ESXi datastore
• Place the ESXi host in Maintenance mode
• SSH to ESXi Host using putty
• Run the upgrade command , replace the DATASTORE-UUID with the UUID of your datastore where you have uploaded the Offline Bundle

esxcli software vib update -d /vmfs/volumes/<DATASTORE-UUID>/update-from-esxi6.5-xxx.zip

• once done, reboot the host using below command
• Reboot
• Exit maintenance mode

Upgrade Compatibility Checks

https://www.vmware.com/resources/compatibility/sim/interop_matrix.php#upgrade&solution=1

VMware Hardware Compatibility List

https://www.vmware.com/resources/compatibility/search.php