mp4 files not exporting and not viewing in the program

I'm using premiere Pro I've never had a problem before until just recently I take an MP4 file I import it I added to my sequence everything works great but then when I export my MP4 file you can only hear audio. So the rest of the videos work and show up fine those are.MOV but like I said I've never had this problem before another thing I noticed is all the videos that I have in there when I click on them like I'm going to hit the play button it shows up in the program in the top right but the MP fours they only show up when I click and drag through the video but when I let go of the dragging it doesn't show the video and the program somethings going on I'm not too sure what it is please help.

settings attached.