Thread:Extension talk:MsUpload/Uncaught ReferenceError: wgFileExtensions is not defined - Mediawiki 1.25

I am testing out Visual Editor on Mediawiki version 1.25 and the MSUpload extension just hangs when dropping an image on the drop box area. It just sits with the progress wheel and doesn't progress any further. I tried this on our other wiki which is a mirror of this but running the current 1.24 version and this works perfect with the same localsettings.php settings. I have checked the debug came across this error: "Uncaught ReferenceError: wgFileExtensions is not defined" The wgFileExtensions section which lists all the accepted file extension is set correctly in the localsettings.php file correctly and as I said previously works fine on the other version (1.24) Any ideas on how to fix this please or where to start looking?

Thanks in advance, Tony