You have run out of RAM (how much available RAM do you have?) One thing: 8k ×8k at 90 fps? This is a waaay too high for any existing system. Most of PC's can have hard time at playing 4k at 30 fps, but a modern one should do it. Here you are trying to make a video that has 24 times more data to deal with than a 4k video. This simply can't work and I'm even not sure that such a format can even be encoded with any codec, not to speak about playing it anywhere.