reirei

Okay guys,Im new with video pad and really need help with this topic.I have been editing videos with videopad and made few videos for gaming that i posted on youtube. All the videos i have are mp4 format and have been playing normaly in videopad.Few days ago i wanted to edit a different mp4 video.When i opened it in videopad the video was not showing (the whole video is black) and the only thing that plays is audio.Wasnt sure if the video was damaged so i checked it on windows media player and the video is perfectly fine and plays like it normaly does. I dont know if i should change the format of it or what,because i was able to edit it in mp4 format before. Please heeelp >_< I need to make a new video but havent been able for 2 weeks already cause i cant find the reason the videopad wont read it. >_< Thank you~