I am running NextCloud 21.0.0. These are the warnings on the Overview section (Security & setup warnings) on my server settings:
[Warning 1] * Your web server is not properly set up to resolve “/.well-known/webfinger”. Further information can be found in the [documentation]
[Warning 2] * Your web server is not properly set up to resolve “/.well-known/nodeinfo”. Further information can be found in the [documentation]
[Warning 3] * Your web server is not properly set up to resolve “/.well-known/caldav”. Further information can be found in the [documentation]
[Warning 4] * Your web server is not properly set up to resolve “/.well-known/carddav”. Further information can be found in the [documentation]
Let me label these warnings from Warning 1 to Warning 4.
Nextcloud resides in the subfolder /nextcloud on my Apache server and the DocumentRoot is set to “var/www/html/nextcloud” in default-ssl.conf. I can confirm that these lines that allow .htaccess to override configurations in the Apache server help to get ride of Warning 1 and Warning 2. I did not have to add any RewriteRule line in .htaccess.
<Directory /var/www/html/nextcloud>
Options Indexes FollowSymLinks MultiViews
AllowOverride All
Order allow,deny
allow from all
</Directory>
Reference: Apache .htaccess file - Examples and Common Uses | DigitalOcean
I am not yet able to get rid of Warning 3 and Warning 4
[Updated 3/29/2021: I follow the instructions here and it took care of Warning 3 and Warning 4 → Caldav and carddav error resolving - #8 by mable]