what Is Problem

[Xp.Warrior]

I Upgrade My vbulletin 3.8.2 to vbulletin3.8.6 Beacuse My hosting php5.3x version Not Supported And Showing Errors In 3.8.2 But Now I Upgrade To vbulletin 3.8.6 When I Go To Admin Cp Then Show Thease Errors
Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@yahoo-rules.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Thanks In Advanced

[PinkMilk]

"Internal Server Error" is usually a .htaccess issue, make sure everything is correct within that file.

Look for a line something like this:
ErrorDocument 404 /404.php

As as it states in the error message:
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

[Xp.Warrior]

Not Understand
Brother Explan Me step by step How To Fix This
Now I More Upgrade To vbulletin 3.8.7 But Same Errors Show

--------------- Added 1337190260 at 1337190260 ---------------

I Sure This Is Not Server Problem Beacuse Today I Download Backup Of My Forum
And Then I Insatll New vbulletin 3.8.6 And Working Perfectly
But When I Restore My Backup And Go To Admincp Then Again Show This Error