After upgrading to a new version with an existing database, you encounter something like:
Caught MultipleObjectsReturned while rendering: get() returned more than one CacheKey – it returned 12! Lookup parameters were {‘key’: ‘cms-menu_nodes_en_1_1_user’, ‘language’: ‘en’, ‘site’: 1L}
What has happened is that your database contains some old cache data in the menus_cachekey table. Just delete all those entries.
Setting an x-frame-options header with DENY value will break certain toolbar functionality. This is independent of any x-frame-options functionality offerred by django CMS.
Example error in browser console (as worded by Chrome):
Uncaught SecurityError: Failed to read the ‘contentDocument’ property from ‘HTMLIFrameElement’: Sandbox access violation: Blocked a frame at “http://0.0.0.0:8000” from accessing a frame at “null”. The frame being accessed is sandboxed and lacks the “allow-same-origin” flag.
Some examples, places that might set a x-frame-options header:
If you set a x-frame-options header independently from DjangoCMS, because the value is SAMEORIGIN or allow frames from certain URIs ALLOW-FROM uri. For more information, please read X-Frame-Options article on Mozilla Developer Network:
https://developer.mozilla.org/en-US/docs/Web/HTTP/X-Frame-Options