Well, I converted some videos from .MOV to .MP4. The video's time was 7:21 at once (.MOV), but when I uploaded it to YT with .mp4 codec, the video was cut in half.
This time the video was 3:01 and was incomplete. So, what happened?
did you use a trial version of a software?
What software did you use?
After you converted it to MP4...did you test it before uploading? If so, was it the complete clip, or was it cut short?
If the MP4 is complete, did you wait until the end of the upload process? YouTube upload may be quite slow and there is a progress bar. You must wait until it tells you it is complete.