I have upgraded my app from version 6.10 to 7.2 and it seems the treeview widget has broken. Whenever I add a new node, the system throws an unexpected error ("An error occured, please contact your system administrator."). In the browser error "Error: Cannot read property 'set' of undefined" is thrown. Anyone know a workaround? Or does the widget needs to be updated to version 7.2?
I made a quick test and it seems that 'dojo.html' is not defined in the widget.
Looks like a Bug. You should file a bug report with a simple test project.