A cloud-based identity and access management service for securing user authentication and resource access
There is no supported information here indicating a user limit for assigning an enterprise application. Since 24 other users work, focus on user-specific access conditions instead of a capacity limit.
For this user, check these areas in order:
- Verify the app assignment model
- In Microsoft Entra admin center go to Entra ID > Enterprise apps > All applications > [the app].
- Open Properties and check Assignment required?
- If it is Yes, the user must be explicitly assigned directly or through the correct group.
- Reconfirm the user is assigned in the app
- In the app, open Users and groups and verify the affected user is listed.
- If access is group-based, verify the user is a valid member of that exact assigned group.
- A known sign-in failure in this area is AADSTS50105, which occurs when the user is not considered directly assigned or in a group with access.
- Check whether consent is the real blocker
- The message about lacking admin permissions usually points to consent, not basic app assignment.
- If the app is requesting administrator-level permissions, a Privileged Role Administrator must grant consent on behalf of the organization.
- If the app is requesting only user-level permissions, the user must be able to complete user consent.
- Compare requested vs granted permissions for the app
- Go to Entra ID > Enterprise apps > All applications > [the app] > Permissions.
- Review the already granted permissions.
- Select Grant admin consent to open the consent prompt and compare the permissions being requested with the permissions already granted.
- If permissions appear in the consent prompt but not on the permissions page, those permissions have not yet been consented to and can cause unexpected consent or admin approval prompts.
- Do not accept tenant-wide admin consent unless that is intended.
- Check tenant user-consent settings
- Go to Enterprise applications > Consent and permissions.
- If Do not allow user consent is configured, users cannot consent for themselves, and an admin must grant consent for the app.
- Check whether assignment-required plus missing admin consent is causing the failure
- If Assignment required? is Yes and tenant-wide admin consent was never provided, the user can receive admin-consent-related errors even when assigned.
- Check other user-specific sign-in blockers
- Since only one user is affected, verify the user account is not locked, is enabled, and is not being blocked by Conditional Access or MFA-related conditions.
- Microsoft’s troubleshooting guidance for Microsoft applications specifically calls out account status, MFA, and Conditional Access as common causes when one user fails and others succeed.
Most likely causes in this scenario:
- The app is requesting permissions that require admin consent.
- User consent is disabled tenant-wide.
- Assignment required is enabled and the user is not effectively assigned in the way the app expects.
- A Conditional Access or account-specific issue is affecting only this user.
- Unexpected consent prompt when signing in to an application
- Unexpected error when performing consent to an application
- Problems signing in to a Microsoft application
- Manage access to an application
- I have Entra federated with Okta. One of my users is getting this error: AADSTS50105: The signed in user is blocked because they are not a direct member of a group with access. My problem is that they are a member of a group with access and assigned app. - Microsoft Q&A