Schemus is unable to access Exchange Online to query for mail, users and groups.

The settings appear to be invalid. Unable to access Exchange Online

This issue occurs for one of the following reasons:

• You enter an incorrect user name or password.
• You try to sign in to the service by using an account that doesn't have access to Exchange Online.
• The default value for Exchange Online in the Access URL has been changed.
• Multi-Factor Authentication (MFA) is required by Exchange Online to access Powershell

Confirm the username and password are correct by signing directly into Office 365 with the account credentials.

Ensure the account used has the proper access to Exchange Online. This can be done using the syntax: Get-User -Identity <UserIdentity> | Format-List RemotePowerShellEnabled

• If the account does not have access, this can be added using the Exchange admin center in Office 365 via the follow these steps:
  1. Sign in to the Office 365 portal as an administrator.
  2. Click Admin >  Exchange.
  3. Click Permissions > Admin roles.
  4. Double-click the role group to which you want to add the user.
     For example, if you want the user to have full access that includes Windows PowerShell, double-click Organization Management.
  5. To add the user to the list, click Add + under Members.
  6. Click Save.

When Schemus established a remote session to https://ps.outlook.com/powershell, the URL automatically redirects it to servers hosting your Office 365 resources, once the remote session is created, it will then import that session’s commands (get-user, get-contact, get-group, get-recipient) into your local Windows PowerShell session and it will begin to use these cmdlets to retrieve attributes from the Office 365 services.

The default value for Exchange Online in the Access URL should not need to be changed in the schemus configuration. If you change this line by accident, click on the Reset Defaults buttons to restore the original value. This can be changed under Edit > Settings > Exchange Online > Reset Defaults. The controls allow you to set the default details for connecting to the Exchange Online server.

Click on the following link to find the permissions required to run any Exchange Online cmdlet.

If Multi-Factor Authentication (MFA) is required by Exchange Online to access Powershell, Schemus does not support this feature and Apps Password will need to be used.

Steps for setup can be found at :

https://docs.microsoft.com/en-us/azure/active-directory/user-help/multi-factor-authentication-end-user-app-passwords