I created a video and I added two separate clips to make one video.  The first part of video does not appear.  I can see video clips on movie but when I press play a black screen with no video and no sound appears.  The second part of the video will play the video.  I added screens before and at end of videos to create credits and such.  I also added at first part of video the video stabilization - anti-shake and wobble to video.  I noticed it is not on second part of video.  

I have windows 8 and this is my first video project I have created.

Can anyone please suggest how to correct this problem??

Thanks for any assistance!!