I am running
Sibelius 8.1.1
VDL 2.5.5
Mac OS X El Capitan 10.11.4
I have the VDL SoundSet 7.0a completely downloaded and in as many folders as I possibly can, but I can not seem to find the VDL SoundSet 7.0a label in the drop down menu of playback configurations no matter where I put the .xml link. I have attached screenshots of anything I believe to be useful to you.