What version are you running?
4.0.11 + latest powerpack
What's the URL of the page this enhancement relates to, if any?
any page that need to access versionvault data (ie the diff tab in a review)
Describe the enhancement and the motivation for it.
With the powerpack and versionvault integration.

You define a repository and assign a versionvault view (path) to access it.

In order to get the content or accessing file (like viewing the diff tab) the view need to be started. This is not done via reviewboard and need to be done manually. If the user/admin reboot or for any reasons (like a backup) stop VV the view will go down. They have to remember to manually restart ALL repositories view or face a server 500 error with no error message.
Enhancement:

1. test if the path/view is accessible (and something inside) and if its not, show an error instead of crashing with an error 500

2. or better, for dynamic view, start the view in the background (cleartool startview <viewtag> where the viewtag would be the path for the repository (not vob tag included))
What operating system are you using? What browser?
Linux
Please provide any additional information below.