Krushim

I have a video with 3 mp4 clips in it. Two were dl'd from youtube but the third I made with xsplit. I put the three clips on a sequence with the youtube ones first then mine at the end as an outro. When it renders the video for the youtube clips shows but for mine at the end only the audio comes through while the video doesn't render for some reason. It looks fine in the preview but not in the export. I've tried different compressions all to the same effect so far. Why would this happen? Krushim