edgeAADSTS50196: The server terminated an operation because it encountered a client request loop. Please contact your app vendor.

Answer is in the doc:

"Clients that issue duplicate requests multiple times will be sent an*invalid_grant error: AADSTS50196: The server terminated an operation because it encountered a loop while processing a request**."*

https://docs.microsoft.com/en-us/azure/active-directory/develop/reference-breaking-changes#march-2019

Thank you very much!

I reset my laptop 3 times yesterday hoping that it solved 3 problems.

1. you answered
2. I am constantly asked to sign in to the fact that it is very annoying & I cannot get any work done.
3. I am having a hard time getting my previously installed basic Google apps reinstalled.

I did find another of my unused emails in "users" that I straightened out.

I am so pc illiterate that these things take me forever so I a very thankful for knowledgible people like yourself!

wer is in the doc:

"Clients that issue duplicate requests multiple times will be sent an*invalid_grant error: AADSTS50196: The server terminated an operation because it encountered a loop while processing a request**."*

https://docs.microsoft.com/en-us/azure/active-directory/develop/reference-breaking-changes#march-2019

Well that does not tell you why the client is misbehaving. It can have several reasons:

on my computer it is ublock origin (adblocker) in chrome which seems to block an important part of the login communication. 

In Edge  and  ms-appstore it is the simple fact that I reinstalled yesterday Windows 10 from an 1903 usb drive and the updates had not finished .

Once they were updated to the last versions the problem went away .

This is also why it can happen on new computers as "new" does not mean "up to date" .

Most new computers have a quite big time gap between the factory installed Versions and the last up to date versions of most software.