I am getting two similar problems in different places after upgrading to 6.5.12. Both seem to be caused by the inclusion of <guide:includeGuideContainer/> in our forms template, if there is more info about what this library tag is doing internally that would be great. The first problem happens when trying to load adaptive forms in workspace from a start point. The error "Error in getting unbound xml partnull" in browser. I also get a similar thing happening when opening a form that has data passed as parameters in its url.
Here are the errors from the jog (notice I removed paths for privacy reasons):
GET (removed path) HTTP/1.1] com.adobe.aemds.guide.service.impl.GuideModelTransformerImpl Error in creating data merged json from data Ref
GET (removed path) HTTP/1.1] com.day.cq.wcm.tags.IncludeTag Error while executing script body.jsp org.apache.sling.api.scripting.ScriptEvaluationException:
GET (removed path) HTTP/1.1] org.apache.sling.engine.impl.SlingRequestProcessorImpl service: Uncaught SlingException com.adobe.aemds.guide.service.GuideException: Error in getting unbound xml partnull