Today I was busy with a vCenter server upgrade to vCenter 5 update 3. Everything went fine except the vCenter Update manager installation. I received the following error:

A quick search on the interweb for “Error 25113.Setup failed to generate the JRE SSL keys” and I found a VMware KB with the exact issue.   According to VMware KB 2059567 all version of vSphere 5.x are affected by this bug.  Not sure if this is common knowledge to everyone else, but this is the first time I have seen this error.  I have done many upgrades and have never seen this before.  The solution is simple. Just stop the vCenter Update Manager service before starting the upgrade. Right after stopping the service, the installation was successful.