Although the following process in itself will not enable those buttons directly again, it will allow you to perform an update of the appliance from a command line… which should enable those buttons again after the update is completed. This method should also only be performed for a minor update to the appliance… I’ll write a slightly different post on the process to upgrade to a major release:
/opt/vmware/bin/vamicli update --check
/opt/vmware/bin/vamicli update --install latest --accepteula
This update will actually now take approximately 20 minutes to complete, the appliance will then reboot and you should then be presented with the new version.
Please note that you should log back onto the appliance and perform a reboot of it before the new version takes effect.