Had the same result. After clicking on the new tree’s icon, went right to the screen jacoline sent. Was not given an option to use a GEDCOM of my choosing, see attachment. As you can see I tried it twice. Used the latest version on the Twitter link.
My local install uses Apache 2.4.27, PHP 7.1.9, and MariaDB 10.2.8. Kiwitrees Version 3.2.2 runs perfectly. All settings including permissions are exactly the same.