MAC Yosemite: Empty screen after Sophie installing

[Stephan]

Hi, the XAMPP installation works just fine on MAC OS Yosemite (on my local notebook). But after Sophie installing I have got a empty screen. Sophie does not start. I have used the Sophie documentation for all steps (adaptation document directory, "sophie" read/write-permissions, mySql: new database "sophie", virtual host entries in httpd.conf) . After this with local.sophielabs.net I get a empty screen. 

Can anyone help me? 

Thanks. Stephan