@richard-wirski

Hi and welcome to the forum.

If you require help with the issues you are having then we need more information:

• Computer specification and program version, see this topic for what is required and please quote processor and graphics card make/model in full.
  
  I would suggest you put this information in your profile signature so we do not have to keep asking for it.
   
• Are the graphics card drivers up to date?
   
• Download and install MediaInfo and analyse one of the source video clips and post the results, see this tutorial on how to setup MediaInfo and analyse a video clip for all the data required.  
     
• Export preset your are using, and did you make any changes to it?

John EB
Forum Moderator