I have been experiencing a very frustrating bug with the frame serving to Handbrake. The problem is not with Handbrake but with Vegas( Pro 14, Build 252, but not new to it) because it appears as soon as the frame server is started and disappears as soon as the frame server exits. I thought I found the solution by disabling all GPU activity in Vegas, but it has appeared again. It seems that it appears with any project that is longer than 2 minutes, which is really frustrating as the only other option I have is MainConcept AVC (my projects are 4k, 24 fps), which, unfortunately, is excruciatingly slow.
Anyway, please see the enclosed video which shows exactly what happens, namely, the moment the frame server starts, Vegas is feeding it total garbage, which it also shows in the preview. In this case I just aborted it because I know from experience that the same garbage would appear in the final render from Handbrake (GIGO).
Ironically, this footage was rendered by Handbrake using the same frame server it did not like with the longer project.