While we were upgrading one of our VCSA 6.5 vCenter appliances to 6.5 Update 1, I ran into an error Stage failed when trying to check for updates within the port 5480 admin interface.
Since migrating to the new Photon OS based vCenter 6.5 VCSA Appliance, we’ve had issues with alerts not being sent to email.
As it turns out, there’s a problem with the internal configuration not being updated properly. VMware is aware of it and should hopefully fix it at some stage.
For now you can follow the workaround below.