Can I just create the file "header.php"?
I did that but I am just getting:
Warning: Cannot modify header information - headers already sent by (output started at .../wiki/extensions/Header/Header.php:6) in .../wiki/includes/WebResponse.php on line 37
I read that this means there is a problem with "header.php".
I created the file with Notepad++, not with Windows Notepad to have the right "coding"
and
there is nothing (even not whitespace) before the <?php tag
Can anyone help here? Thanks.