A couple of things to try...
1. Have nothing but PS open at the time.
Close anything that you don't need for the duration of rendering the video.
2. I assume you have the PSD file saved, if not, finish your edit and SAVE IT!
Close PS.
Re-open your file BUT DO NOT PLAY THE VIDEO.
Try 'Render Video...' again and see if it's any better.
The theory here is that when you 'Play' the video for the first time after an edit it's stored in memory. This obviously isn't desirable as you need as much memory as possible for video editing...that and the fact PS is lousy at memory management.
Failing that you could try splitting the video up into chunks that PS can handle and join them back together in some other software....FFMPEG is pretty good at most things video, joining included.
One other thing too, PS doesn't clear unused memory so it may be just a simple case of closing and opening PS again to clear it....if it still hangs then make sure there is enough room for the scratch disc to operate....it'll only get used when the memory is low but provision for it is made almost as soon as PS is open...whether you need it or not...it gets deleted when PS closes.
Other than that, I'd suggest a video editor. PS is primarily image editing software, Video Editing Software would handle this much better.
Throwing more memory at it won't really help, you just need to get PS to use what you have properly....which unfortunately is not easy.
Regards.
MrToM.
