AADSTS50049: NoSuchInstanceForDiscovery

The authority your app was given isn't a known Microsoft Entra instance, often a typo in the sign-in host or a host from the wrong cloud.

How to fix it

Use the sign-in host for your tenant's cloud exactly as Microsoft lists it.

Your tenant or subscription	Sign-in host
Commercial Microsoft 365 and Azure, and GCC tenants	`login.microsoftonline.com`
GCC High and DoD tenants, and Azure Government	`login.microsoftonline.us`

Note: Microsoft's row for this code doesn't mention clouds. The cause above is the common one in US government setups, so check it against yours.

“AADSTS50049 | NoSuchInstanceForDiscovery - Unknown or invalid instance.”

“Microsoft Entra ID for US Government | https://login.microsoftonline.us” (National clouds)

pip install fairfax
fairfax explain AADSTS50049 --tenant gcchigh      # or paste the whole error message

To find the commercial sign-in host in your code before it fails, run fairfax scan src/ --tenant gcchigh --azure government.