STARTMOVIECAPTURE no longer works in a single player game

STARTMOVIECAPTURE no longer works in a single player game

[Link Removed] looked into the code and found that it's in the EditorServer code. We tried it with two players and then it appears to work. It worked in older builds (tested 4.9 and 4.10).

If this was replaced with r.DumpingMovie, then this can be closed. However, r.DumpingMovie only appears to output an image sequence.

Note: Also occurs with StopMovieCapture command

Regression: YES

Worked: 2872498 (4.10.4)
Broken: 2946394 (4.11.2)

1. Launch any game session with only one player (PIE is fine)
2. Hit ~ twice
3. Enter the STARTMOVIECAPTURE console command

4. Result: "Command not recognized"
   Expected: Movie capture begins and is saved to Saved/VideoCaptures as an avi