This morning, I tried to use PI Datalink to get event frame data from an asset server I added recently.
Datalink was unable to connect to the AF server, however, PI Builder was able to connect to the asset server.
I confirmed the security on the asset server was set to allow me access.
Then, I remembered the Excel session had been open since before the asset server was added to my list of asset servers.
Closed all Excel instances and restarted... connections completed from both Datalink and PI Builder.
So... why can PI Builder see asset servers that have been added after the add-in was initialized, but PI Datalink can't?