After a computer rebuild I reinstalled Movie Edit Pro Plus 18 and then performed all the updates. I then tried to edit a Gopro Fusion 360 .MOV file. Of course it told me I need to install QuickTime which I did. I tried again and no longer got an error message but there was sound only no video. Since then I have uninstalled and reinstalled QuickTime (just in case) but no difference. It always worked before the reinstall and there have been no hardware changes just a reinstall of windows 10. mp4 format play fine

The Computer is Intel I7 5820K Overclocked 4.0GHz HEX Core, Asus X99-A DDR4 32gb with a pair of AMD R9-200 graphics cards at 4k

Any suggestions appreciated.