Signals: When attempting to log in a new user sees the error "User is not assigned to this application"

New users are unable to authenticate in Signals after being correctly created and assigned licenses in the Signals application by the administrator with a message similar to the following:

MS Entra:

Sorry, but we're having trouble signing you in.

AADSTS50105: Your administrator has configured the application [Entra app name] ('2663b956-ba1d-4f5e-bda6-149a3fceb9fa') to block users unless they are specifically granted ('assigned') access to the application. The signed in user [user email address] is blocked because they are not a direct member of a group with access, nor had access directly assigned by an administrator. Please contact your administrator to assign access to this application.

Okta:

User is not assigned to this application.

Cause: This occurs when the user has not been properly assigned to the Signals application within the organization's Identity Provider (IdP) system, such as Azure AD/Entra ID, Okta, or other SAML authentication providers.

Solution: Request your local IT Team to assign the user to the Signals application within the Identity Provider system used by your company/institution.