When I created a test app, I only referenced OSIsoft.AFSDK. When I build, it copies over OSIsoft.PISDK.dll, OSIsoft.PISDKCommon.dll, and OSIsoft.PITimeServer.dll (link to screenshot) into the app/bin folder as well.
As far as I can tell I am stumped on what is bringing in those libraries.
It's a problem for me because I get the following message. (another link to a screenshot)