I have had two different issues for rendering not as a playable whole video.
a) If I pick FFmpeg, The videos are titled WarriorHunters_0000001-61167, WarriorHunters_0010001-61167, WarriorHunters_0020001-61167 and it is three different videos, but for instance WH_002 has a "ghost" 00:00 - 25:00 and only has video there for 25:00 - 37:00.
b) If I pick AVI raw, it is a 430 GB (!!!) file that also launches and only plays the first 15 seconds before stopping.
It is worth noting, a lot of the seams in the FFmpeg version are near where I do long pan-and-zooms with keyframes.