A lot of questions, all of which is looking for valuable information in the hope we can find a cause.  I often have a render complete the sequence with only part of the picture, yet it will do a full render the second or third time.  On most occasions I do a render in que and it will complete without problems.  I have not been able to pin down the cause but it seems to be related to the size of the render (pixel X pixel) rather than the size of the scene.

 

 

I use Poser 13 on Windows 11 - For Scene set up I use a Geekcom A5 -  Ryzen 9 5900HX, with 64 gig ram and 3 TB  storage, mini PC with final rendering done on normal sized desktop using an AMD Ryzen Threadipper 1950X CPU, Corsair Hydro H100i CPU cooler, 3XS EVGA GTX 1080i SC with 11g Ram, 4 X 16gig Corsair DDR4 Ram and a Corsair RM 100 PSU .   The desktop is in a remote location with rendering done via Queue Manager which gives me a clearer desktop and quieter computer room.