Don't fetch the editor for XML courses

lms/djangoapps/instructor/views/legacy.py

@@ -792,17 +792,17 @@ def instructor_dashboard(request, course_id):
     else:
         instructor_tasks = None
 
+    # determine if this is a studio-backed course so we can 1) provide a link to edit this course in studio
+    # 2) enable course email
+    is_studio_course = modulestore().get_modulestore_type(course_id) == MONGO_MODULESTORE_TYPE
+
+    email_editor = None
     # HTML editor for email
-    if idash_mode == 'Email':
+    if idash_mode == 'Email' and is_studio_course:
         html_module = HtmlDescriptor(course.system, {'data': html_message})
         email_editor = wrap_xmodule(html_module.get_html, html_module, 'xmodule_edit.html')()
-    else:
-        email_editor = None
 
-    # determine if this is a studio-backed course so we can 1) provide a link to edit this course in studio
-    # 2) enable course email
     studio_url = None
-    is_studio_course = modulestore().get_modulestore_type(course_id) == MONGO_MODULESTORE_TYPE
     if is_studio_course:
         studio_url = get_cms_course_link_by_id(course_id)