Thread:Project:Support desk/Errors on load.php in Apache logfile

Dear sir/madam,

Since I'm using MediaWiki 1.23.1, I have a lot of times that the CSS file for the application is not loading when I open a page. When I refresh the page, it loads and my page looks fine. This happends multiple times each day. When I was looking in the Apache Error log for the MediaWiki site, I found the following line on the times of the error I receive:

When looking through the load.php file, I noticed the $wgRequest object isn't defined before calling the checkUrlExtension method:

I cannot find anyone else on the Internet with the same issue and cannot find anything on the MediaWiki site, so I'm almost 100% sure it has to do with my settings. Can anyone give me a pointer to the reason of this strange behaviour?

Wiki-url: https://wiki.dstark.nl/ (ignore the certificate warning, the certificate is not signed by any third party CA's)

Application versions:
 * MediaWiki: 1.23.1
 * PHP: 5.4.4
 * MySQL: 5.5.37

Installed module:
 * CategoryTree – (b879dbd) 19:58, 24 June 2014
 * SyntaxHighlight - 1.0.8.11-wmf1
 * MobileFrontend – (f4fabf4) 19:32, 26 June 2014

Kind regards, Daryl Stark