XF 1.5 HTTPS redirect loop ERR_TOO_MANY_REDIRECTS

[supercars]

Hi, our forum is installed in a subdirectory called /forum, we have activated SSL but when we redirect HTTP to HTTPS from htaccess, forum not opening its showing a "ERR_TOO_MANY_REDIRECTS", how can I solve this?

Our htaccess content

#    Mod_security can interfere with uploading of content such as attachments. If you
#    cannot attach files, remove the "#" from the lines below.
#<IfModule mod_security.c>
#    SecFilterEngine Off
#    SecFilterScanPOST Off
#</IfModule>



ErrorDocument 401 default
ErrorDocument 403 default
ErrorDocument 404 default
ErrorDocument 405 default
ErrorDocument 406 default
ErrorDocument 500 default
ErrorDocument 501 default
ErrorDocument 503 default

<IfModule mod_rewrite.c>
    RewriteEngine On

    #    If you are having problems with the rewrite rules, remove the "#" from the
    #    line that begins "RewriteBase" below. You will also have to change the path
    #    of the rewrite to reflect the path to your XenForo installation.
    #RewriteBase /forum

    #    This line may be needed to enable WebDAV editing with PHP as a CGI.
    #RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
    #RewriteCond %{HTTP_HOST} ^supercars\.net$ [NC]
    #RewriteCond %{HTTPS} off
    #RewriteRule ^(.*)$ https://www.supercars.net/forum/$1 [R=301,L]


    RewriteCond %{REQUEST_FILENAME} -f [OR]
    RewriteCond %{REQUEST_FILENAME} -l [OR]
    RewriteCond %{REQUEST_FILENAME} -d
    RewriteRule ^.*$ - [NC,L]
    RewriteRule ^(data/|js/|styles/|install/|favicon\.ico|crossdomain\.xml|robots\.txt) - [NC,L]
    RewriteRule ^.*$ index.php [NC,L]
</IfModule>

 

[Floyd R Turbo]

Not sure if this is the cause but it looks like you're trying to correct 2 conditions with one rule, I do it like this

RewriteCond %{HTTP_HOST} ^myforum.org$ [NC]
RewriteRule ^(.*)$ https://www.myforum.org/$1 [R=301,L]

RewriteCond %{HTTPS} off
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]