Sitecore 10 - Error while getting client credentials token: invalid_client

 This is a very common error while working on Sitecore 10 with SCS, Today again I got this error so I thoughts it's good to write a blog on the error, here is the complete details

The full error is here

SerPush

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Executing: .\CakeFiles\Serialization.ps1 -CMHost "https://yoursite.localhost" -IDHost "https://yoursite.localhost" -CLISecret "Bm1bGYPIO7s5Xt0F" -u

Error while getting client credentials token: invalid_client

Client credentials authentication configured without a client secret. Ensure to set the SITECORE_DEFAULT_CLIENT_SECRET environment variable before using this environment.

Login information has been saved.

Client Credentials: Client Secret was not defined. Must be added to default endpoint.

I tried to reset the config and now got the below error 

You are not authorized to perform the task you are attempting. You may need to be assigned additional permissions.

I restarted PowerShell and run under the admin mode (Although this was already under the Admin mode) that has resolved the issue