Hi Thomas,
Not sure if this will help but I had this issue immediately after I upgraded to OS X 10.10.4. Prior to the upgrade Servoy developer (7.4.4) was running perfectly with no Java 6 installed but after the upgrade, as soon as I started Developer, it gave me the message you have above. A simple reboot of the affected machine restored everything to working order again.
Have you rebooted since you installed 10.10.4?
Steve