Based on my experience, the only sure way is to run the version of VRD you want VAP to use with "Run as Administrator" (right-click shortcut and select that) one time prior to starting VAP. You only need to do this when switching between VRD versions or (maybe) after upgrading a VRD version.
Also you should be using at least version 1.19 of VAP, preferably the latest version (currently 1.21). I provide support only for the latest release.