The username you entered is not a member of this organization

Error Message

When logging in to an ArcGIS Online organization from ArcGIS Pro, ArcMap or the ArcGIS Online website using the organization's username and password, the following error message is returned:

Error:   
The username you entered is not a member of this organization.

The image below shows the error message displayed when attempting to log in to ArcGIS Online from ArcGIS Pro.

The image below shows the error message displayed when attempting to log in to ArcGIS Online from ArcMap.

The image below shows the error message displayed when attempting to log in to ArcGIS Online from the ArcGIS Online website.

Cause

In ArcGIS Online

• This issue occurs when a user attempts to log in as soon as a user from a different organization has logged out from the sign in page. The URL of the sign in page contains the short URL of the previous organization logged in. ArcGIS Online assumes the second username belongs to the same organization.

The image below shows the short URL and the organization's name on the sign in page after a user has logged out.

• A user attempts to log in to an organizational account using a public account.

In ArcGIS Pro and ArcMap

• The portal connection is configured with the URL of a specific organization. Therefore, when a user attempts to log in as soon as a user from a different organization has logged out, ArcGIS Online assumes the second user is from the same organization.
• A user attempts to log in to an organizational account using a public account.

Solution or Workaround

Complete the steps below to resolve the issue.

In ArcGIS Online

• Remove the short URL of the previous organization and change the URL to the current user's organization name. For example, https://[short organization name].maps.arcgis.com/. Press Enter. Log in using the username and the password of the required organization.
• Log in to ArcGIS Online using the correct organizational username and password.

In ArcGIS Pro or ArcMap

• Add the short URL of the organization's portal in ArcGIS Pro or ArcMap and connect to the organization portal. For more information, refer to ArcGIS Pro: Add a portal connection and ArcMap: Add portal connections.

Note:
Optionally, switch the portal URL to the default ArcGIS Online connection when required.

• Log in to ArcGIS Online using the correct organizational username and password.