this may be a dirty solution but it helped me when I encountered the same error message trying to start a game in which the first action is to load a huge scene.
did setting the “g.TimeoutForBlockOnRenderFence” to 9999999 not help?
If you set this up to be executed on all machines but the problem persists on some, then it may have to do with the speed of the disk it is running on. If you can, make sure the game runs on an SSD.