The compatibility tool should be around 1.07MB in size? If it's not, then I suspect the tool did not fully download. It could be the browser or system security preventing straight up executable file exe downloads. Check your browser download tab to see if the application finished downloading and if you can change settings in order to finish or try again if not.
What is your graphics card? I suspect the warning may be because the adrenaline software doesn't recognise the older card. Some suggest windows can be a problem in overwriting or updating files. Suggestions are that a removal and reinstall of amd software with DDU or amd removal tool, or even uninstalling the amd display driver in device manager may help, eg see here.
