I’ve run into a problem with Rhino 5. While I had Rhino / Grasshopper running, the pan / rotate features stopped working. After closing and re-opening the applications, the left and upper toolbars had disappeared and I got the error message “Root element missing”. I’ve followed the instructions on My toolbars disappeared ! - Rhino V5 [McNeel Wiki] but it doesn’t seem to work. I also tried going into Tools > Options > Toolbars > Restore default but that didn’t work either. Not even deleting and re-installing Rhino seemed to help.
In case this might help I have the following plug-ins installed: Grasshopper, Weaverbird, and Lunchbox.