Thread:Project:Support desk/blank start page after new installation and configuration/reply (8)

No. Setup.php is called after LocalSettings.php. Setting $wgLocaltimezone at the bottom of LocalSettings.php will prevent the relevant code in Setup.php from executing.

Note: Fixing the setting in php.ini, while may be a good idea, is not required to fix your issue. - "So I downloaded and installed the patch - with not much result"

Then you did it wrong :P. The patch will prevent outputting that error. I can still see that error on your wiki.