Earlier today I was trying to download a VM from one of our ESX datastores using the Datastore Browser. Unfortunately, the vSphere Client kept crashing with the error “VpxClient has encountered a user-defined breakpoint” after I chose the destination folder. Some quick research turned up a thread on the VMware Community site which highlights the cause: Datastore browser – user-defined breakpoint

…If you close the VI Client and re-open it as administrator the problem appears to go away…

It appears that VMware is not fully finished preparing the vSphere client for UAC elevation, which is pretty sad, considering Vista shipped with UAC over four and a half years ago. It’s unfortunate to see a company as forward thinking as VMware let their client stagnate so much.