Hello world ! Sorry, poor English but I read the Language barrier thread 
My YunoHost server
Hardware: dedicated distant server (x86)
YunoHost version: 4.1.7.1
Nextcloud version : 20.0.4~ynh1
I have access to my server : Through SSH
Are you in a special context or did you perform some particular tweaking on your YunoHost instance ? : no
Description of my issue
Tested on two distinct servers, same bug.
- After updating the Nextcloud app from v19 to v20, I lost the Yunohost Overlay. As a result, can’t go back to SSO menu, unless changing the url from myserver.noho.st/nextcloud to myserver.noho.st/yunohost/sso.
Reverting to v19 using a backup solve the problem, but re-update the app recreate the bug.
The overlay ynh_overlay.css config file have not been modified in any way.
- I noticed a second bug (one probably being a side effect of the other) : in this case (Nextcloud v20), disconnecting from Nextcloud disconnect from Yunohost too but disconnecting from Yunohost do not disconnect from Nextcloud (the “root” URL myserver.noho.st asks login, but myserver.noho.st/nextcloud is still accessible without relogin).
- Besides, I noticed that sometimes, disconnecting directly from Nextcloud (after having previously connected from the Yunohost SSO) leads to an error message on Nextcloud :
Accès non autorisé
CSRF check failed
(First line could be translated to “Unauthorized Access”, I suppose).
And the Overlay appears.
Those things make me think about a “communication issue” between Nextcloud v20 and Yunohost himself.
If needed, I can run several tests on the less important server (and obviously provide some log or config files).
Thank you for reading, please tell if you encountered this issue (or have the solution ).