I rendered a video with an audio spectrum and i started to watch the video and it looked like the video was fine until it turned black at about 3 min and the audio was still playing. The composition time is the length of the song. IDK what to do PLEASE HELP!!!
Nobody can tell you anything without proper system info or other technical details like exact render and comp settings.
i have windows 7 64 bit and i set to render the video at 1080p and the format was mp4
If you go to the last frame of your composition, is there anything on the screen?
My guess is that your visualizer layer isn't as long as your composition is. Or, if there are 3d layers, maybe your camera layer isn't long enough.
How did you render the MP4? The best practice is to render to an intermediate file out of AE (QuickTime with the PNG codec, for example) and then use the Adobe Media Encoder to create your deliverable (it even has presets for YouTube).