I've just reloaded the plugin in plugin manager.
Tried a render and close on an existing and new model and it worked ok.
Opened the control panel and Rhino stopped responding for about 2-3 minutes. It went to a 'close/wait?' option, I waited and it made it through.
I turned on a ground plane (probably not relevant), rendered, stopped the render after a minute. Now I'm unable to close Rhino - yes except for Task Manager, so no reporting option.
I hope that is a help!