I recall going through the registry procedure described in this post a few months ago when the error message in ccleaner appeared. The procedure worked. Since then, windows 10 has updated a few times. I currently have 10.0.18362 build 18362.
Now, all of a sudden the error message in ccleaner has returned. Relative to what the other posters here are saying about the registry, the Key "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\MicrosoftEdge " doesn't exist (or no longer?? exists). Thus, you can't "navigate" to this key per the instructions @ https://www.ccleaner.com/docs/ccleaner/