I've tried rendering an image using the Cycles render engine. here is the output:(everything looks good)
I tried rendering the same image, but using Radeon ProRender engine. This is how it looks at samples 28/128(not ready yet, it looks fine):
And this is the output.. I don't understand why I get a grey image. Did I miss something ?
EDIT
Here are my blender preferences
I have also installed this from their official website //// i do not know what other settings so show here
My .blend file is this