• Please make sure the file you convert is not corrupted. You can try converting it using our online tool as a test: https://www.videoconverter.com/
  
  
• Try to play it in the program preview from the beginning to the end.
  
  
• If it plays alright all the way through, then try to change the output directory and output format.
  
  
• You can try disabling the currently active accelerations on the menu Settings - Preferences - Accelerations.
  
  
• It is also recommended to check whether your graphic card drivers are up-to-date.