My LocalSettings.php is correct. I think i found the
mistake: My hosting
provider. I tested it on my machine using XAMPP and everything worked
fine. On my webspace, error reporting seems to be turned off. There is
no log file. I have no idea what is happening there and i don't think i
will ever figure it out. I'm going to find another provider.
Place error_reporting( E_ALL ); at the top of your LocalSettings. You
may temporarily show the errors in the page by also adding
Check locally that LocalSettings parses correctly before uploading.
If you didn't check exactly the same file (ie. you did the same changes
on a different copy) I'd still suspect of an error editing it.