"Unable to authenticate your credentials" error when you try to connect to Azure Active Directory. Attempt to execute
Connect-MsolService cmdlet with correct credentials fails with:
PS C:\> $cred=get-Credential PS C:\> Connect-MsolService -Credential $cred Connect-MsolService : Unable to authenticate your credentials. Make sure that your user name is in the format: <username>@<domain>. If this issue persists, contact Support. At line:1 char:1 + Connect-MsolService -Credential $cred + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : OperationStopped: (:) [Connect-MsolService], Mic rosoftOnlineException + FullyQualifiedErrorId : 0x80048862,Microsoft.Online.Administration.Autom ation.ConnectMsolService
Besides conditions described in Microsoft KB article an error may also occur when Microsoft Online Services Sign-In Assistant on the machine where the cmdlet is being executed cannot establish secure communication channel with Microsoft Cloud.
To make sure that affected machine can communicate with Microsoft cloud you can open https://login.microsoftonline.com/ in any browser installed on the machine and verify that there are no security warnings related to untrusted SSL certificates. One of the possible reasons of security warning is absence of one of the CA certificates which is used by Microsoft cloud in Trusted Root Certification Authorities container on the affected machine.
Make sure that all CA certificates which are used by Microsoft cloud are installed on the machine.