Add debug logging of exceptions that happen during rending of studio_view or student_view in Studio

cms/djangoapps/contentstore/views/item.py

@@ -105,6 +105,7 @@ def xblock_handler(request, tag=None, course_id=None, branch=None, version_guid=
                 # dungeon and surface as uneditable, unsaveable, and undeletable
                 # component-goblins.
                 except Exception as exc:                          # pylint: disable=W0703
+                    log.debug("Unable to render studio_view for %r", component, exc_info=True)
                     content = render_to_string('html_error.html', {'message': str(exc)})
 
                 return render_to_response('component.html', {

cms/djangoapps/contentstore/views/preview.py

@@ -159,5 +159,6 @@ def get_preview_html(request, descriptor):
     try:
         content = module.render("student_view").content
     except Exception as exc:                          # pylint: disable=W0703
+        log.debug("Unable to render student_view for %r", module, exc_info=True)
         content = render_to_string('html_error.html', {'message': str(exc)})
     return content