Why does XForms designer display "Unexpected Failure: Internal Server Error"?

when I press on design Xform it gives me this error:

When I press more, this is what it shows: http://pastebin.com/zF7krfhL

Can you send a screenshot of your form schema screen?

When I closed OpenMRS standalone and restarted it, the error went away. not understanding what is causing the errors and why they go away worries me a bit. hope this doesn’t happen when I start implementing OpenMRS in my facility :smiley: Luckily I got you guys to help :grin: