Long video won't play all the way

I rendered an 8 hour long study background video. The temp files generated for the H.264, mp4 file totaled about 90GB and it took a long time after the render for my computer to compile the final video file and when it finished it's only 11GB and will only play for the first 50 minutes. Does anyone know how to address this? I'm not even sure what this problem is called.