That is probably the error, even the log states it, and I remember that (I believe) @freyalupen or was it @YRH said something about a maximum possible size of animations with the used open source codec.
Add: By the way, it is possible that you’ll run soon into the forum’s spambot and troll-barrier for new users¹. If so, we have to continue our conversation tomorrow, or you edit your last post and add all further posts. Please don’t delete former posts when editing, so we don’t lose context!
Hi. I don’t recall the error, but indeed, the image is simply too large (width * height <= 9437184).
@Earth_Nation , I see you’re using ffmpeg bundled with Krita. You could also download a stand-alone ffmpeg and use that instead. I think it should have more encoders available, including ones capable of encoding big frames. I’m using a version from here. You can then set the location of the alternative ffmpeg.exe in “Render Animation” window at the bottom, “FFmpeg location”.