Creating or editing a role where the role is in an invalid state at submission causes a 500 to occur in the view.
Fix commited here: http://github.com/jaswope/chef/commit/eed80c4729a64893454a48ef795d89f6210b2b32
Git repo: git://github.com/jaswope/chef.git
See previous comment.
Thanks, Jon, nice catch. Welcome to chef!
This has been merged and pushed to opscode/master.