Could you please make sure that you are really on 5.5 by creating a file called info.php in /www/htdocs/w00ce9c8/instatising/with the following content:
it seems like version PHP Version 5.3.28-nmm7. I already changed it in the all-inkl.com (my provider) dashboard but nothing changed. It is still PHP Version 5.3.28-nmm7.
The change might take a while to apply. You could try changing it to something else and then back though. And while you are at it, consider upgrading to PHP 7.0, itβs a lot faster.