Thread:Project:Support desk/Blank page and WebStart.php error

Hello. I recently upgraded my mediawiki from version 1.15.4 to 1.18.2. The problem is that when I try to enter the wiki, which is mounted on the localhost, it just displays a blank page, no text, no error message. While checking the error log from apache, I can see the next text:

[error] [client 127.0.0.1] PHP Warning: require(/var/www/includes/WebStart.php): failed to open stream: No such file or directory in /var/www/index.php on line 53 [error] [client 127.0.0.1] PHP Fatal error: require: Failed opening required '/var/www/includes/WebStart.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/index.php on line 53

I have already tried changing permisions to the folders and archives, and also updated all the extensions that were being used and it stills mark that error. If anyone could help me, thank you.