Also did some Google research and tried the following (none of them worked):
Always getting following Error: “Unable to write to Folder Settings because <valuetriedtoset> does not support the folder resource scope.”
In the end i stayed at the default values and added the PHP installdir to my environment path variable and now it works. I’m using Windows 10 Version 1703, newest version of Codemix and Eclipse Oxygen.
Don’t know if this is a bug or I am missing something.