Sounds like either a permissions or memory issue. Check the Windows Event log and see if there is anything under the Application or System sections. Hopefully it wrote something there that will guide you to what the issue is.
Is this a new behavior in a previously working environment or is this a new installation which has never worked successfully? The resolution path is highly dependent on whether this particular installation has ever worked successfully or not.
Run VUgen as administrator and clear some space where the VUgen is installed. If the problem still persists, it might be an issue with LR installation.