Hello Paul. My name is Frank, and have just purchased the Vienna Ensemble Pro 7 plus a few VSL libraries. I seem to be having exactly this same problem, (which I have been discussing with Andreas also).
Essentially, I can easily use VEP7 and the VSynchron Player successfully as standalones. I can connect and run it OK - exactly as per your written manual instructions - to my Pro Tools DAW, Everything works fine if then creating tracks using several different vst products (eg Garritan, Avid XPand, UVI).
BUT, if i then also create and try to connect Steinberg's vst Halion Sonic 3, things go badly wrong. Yes, all of my software is fully licensed and up to date, as is the elicenser. The basic error messages wich arise tell me that both VEP7 and Halion are missing valid id's! and then in Pro tools both items are greyed out saying they are unavailable and/or have an "insufficient resources" error!
So it seems this same issue is still a problem - presumably something to do with Halion, rather than with your product.
PROBLEMSU0020WITHU0020HALIONU0020SONICU0020INU0020VEPROU00207.doc-1696337855373-ec19o.doc