To resolve this issue, use the following methods in the order in which they're presented. After each method, test to see whether the issue is resolved. If the issue isn't resolved, go to the next method.
For users
Method 1: Wait 15 minutes.
Note : If this doesn't resolve the issue, contact your admin
For admins
Method 2: Make sure that the user is allowed to sign in.
To do this, follow these steps:
Sign in to the Office 365 portal as an admin.
Locate the user, and then open the settings for that user.
Under Set sign-in status, click Allowed, and then click Save.
Method 3: Reset the user's password.
As an Office 365 admin, perform a password reset for the user.
Method 4: Reset the user's sign-in status.
Change the sign-in status of the user from Allowed to Blocked, and then change it back to Allowed. To do this, follow these steps:
Sign in to the Office 365 portal as an admin.
Locate the user, and then open the settings for that user.
Under Set sign-in status, click Blocked, and then click Save.
Under Set sign-in status, click Allowed, and then click Save. I tried doing this for one of my client using
Office 365 business premium and
Office 365 ProPlus
