Premiere Rush will not play videos

I have just installed Rush on my computer and am finding that it will not run any videos.
The import is OK, and I can edit and save but cannot play videos.

It shows a blank display where you would expect the video
Have tried several mp4s and all have the same result
Eventually it freezers and I have to shut it down in task Manager.
PC is Intel i5 64Bit 8G

I have put my subcription on hold until I can make it work