I have installed the product, its works ok, but the preview monitor doesn't show the video or pictures that I select. It shows only the audio of the files.
Try turning off the 2 Hardware acceleration option in the Program settings, Import/Export tab.
If that does not work we need more information:
Computer specification and program version number, see this topic for what is required and please quote processor and graphics card make/model in full.
Download and install MediaInfo and analyse one of the clips not showing the image and post the results from the Text view of MediaInfo.