Blank pages in AdminCP

[TrultToast]

Hello vB.org community,

I recently installed vBulletin 3.8.9 from scratch. When ever I save a setting or edit anything via the AdminCP, it gives me this message: "Settings Saved Successfully", but then after that message it reloads a blank page. The category's are still showing on the left but not the main content on the right.

Also when I'm on the search Users page in the AdminCP, and I click any of the options it simply doesn't work... I have to open the link in a new tab for it to work.

The two problems above seem to only happen when I force https using this in my .htaccess file:

RewriteEngine On
# This will enable the Rewrite capabilities

RewriteCond %{HTTPS} !=on
RewriteCond %{HTTP:X-Forwarded-Proto} !https 
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

the next problem is when ever I go to a users profile and click "Edit User Profile" it takes me to the admincp but then shows me this "The requested URL /administrator-panel/user.php?do=edit&u=1 was not found on this server." Yes i renamed admincp to administrator-panel. But that file path does exist.

The AdmincCP seems to force https even when my .htaccess was removed.

Any ideas on how to fix this so it all works fine? ha...
Thank you.

[Zachery]

Try this instead

RewriteEngine On 
RewriteCond %{SERVER_PORT} 80 
RewriteRule ^(.*)$ https://www.example.com/$1 [R,L]

[TrultToast]

My forum is located on a sub domain...
But I did try what you suggested and it puts the forum in a redirect loop.

[Zachery]

RewriteEngine On 
RewriteCond %{SERVER_PORT} 80 
RewriteRule ^(.*)$ https://sub.domain.com/$1 [R,L]

That should be better.