The credentials you have provided are not valid or cannot be used with the ArcGIS Online Living Atlas content configuration you have specified

Error Message

In Portal for ArcGIS, when attempting to allow access to the subscriber or premium ArcGIS Online Living Atlas content, the following error message is returned.

Error:   
The credentials you have provided are not valid or cannot be used with the ArcGIS Online Living Atlas content configuration you have specified.

Cause

An incorrect letter case is used in the login credentials.

Solution or Workaround

Portal for ArcGIS is case-sensitive when accepting credentials from ArcGIS Online. Resolve this issue by using the correct case for the username as in ArcGIS Online.

Note:
In some instances, the ArcGIS Online account must be assigned with the Administrator role. Ensure the member is allocated sufficient credits.