When using vBulletin as a community forums board for your website, the following error messages may be logged by Apache web server in the error logs.

[Sat Mar 21 00:22:22 2015] [error] [client 192.168.1.1] Request exceeded the limit of 10 internal redirects due to probable configuration error. Use ‘LimitInternalRecursion’ to increase the limit if necessary. Use ‘LogLevel debug’ to get a backtrace.
[Sat Mar 21 11:11:11 2015] [error] [client 192.168.1.2] Request exceeded the limit of 10 internal redirects due to probable configuration error. Use ‘LimitInternalRecursion’ to increase the limit if necessary. Use ‘LogLevel debug’ to get a backtrace., referer: https://techjourney.net/threads/some-thread-title

For vBulletin, the issue only happened if you enabled the Mod Rewrite Friendly URLs to increase the site’s ranking in search engines through vBulletion’s Options in Control Panel. And the reason that contributes directly to the error is missing rewrite rules in .htaccess file.

vBulletin requires a .htaccess file with various rewrite rules to support the friendly URLs to be created and placed in the vBulletin directory. However, some of the rewrite rules may have been changed over time, and some rewrite rules may have been added, as vBulletin continues to evolved.

The internal redirects error is directly due to missing rewrite rules, which can happen as older version of .htaccess sample provided by vBulletin is out-of-date, or some rules have been mistakenly left out by the administrator. To be more specific, it’s normally caused by the missing rewrite rules that handled MVC results, as shown in the code below:

# Check MVC result
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^(.*)$ - [NC,L]
RewriteRule ^(.*)$ - [R=404,L]

The block of code above should follow a MVC related rewrite rule as shown below. If you’re missing above rewrite rules, do add them to the .htaccess in the vBulletin root directory.

# MVC
RewriteRule ^(?:(.*?)(?:/|$))(.*|$)$ $1.php?r=$2 [QSA]

For the record, the complete .htaccess recommended by vBulletin for vBulletin 4 which uses Mod Rewrite Friendly URLs is as follow:

RewriteEngine on

# If you are having problems or are using VirtualDocumentRoot, uncomment this line and set it to your vBulletin directory.
# RewriteBase /forum/

# If you are having problems with the rewrite from content/ to content.php, uncomment this line to turn MultiViews off.
# Options -MultiViews

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d

RewriteRule ^.*$ - [NC,L]

# Forum
RewriteRule ^threads/.* showthread.php [QSA]
RewriteRule ^forums/.* forumdisplay.php [QSA]
RewriteRule ^members/.* member.php [QSA]
RewriteRule ^blogs/.* blog.php [QSA]
RewriteRule ^entries/.* entry.php [QSA]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d

RewriteRule ^.*$ - [NC,L]

# MVC
RewriteRule ^(?:(.*?)(?:/|$))(.*|$)$ $1.php?r=$2 [QSA]

# Check MVC result
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^(.*)$ - [NC,L]
RewriteRule ^(.*)$ - [R=404,L]