First problem, when you click on a button to add privileges, the div that comes up does not have a background, making it difficult to use.
Secondly, and most importantly, when you are trying to add privileges, if you forget to select a node, you can click the submit button and the nothing happens.
The simple fix here is to select a node.
This is a usability issue, a background for the div and a simple pop up saying "You must select a node" would be the appropriate thing to do in this situation.
Thanks to everone involved in VCL. It's a wonderful tool.