Concurrent User Limit Reached in Business Central / NAV

When reading data from NAV or Business Central on premise, you might see the below error message: 

“Ihre Programmlizenz lässt nicht zu, dass mehr Benutzer gleichzeitig arbeiten…”
(Your license does not allow more concurrent users. Wait until another user stops using the system.)

What this means:

 Your Microsoft Dynamics NAV/Business Central license has a limited number of concurrent users. Each active session counts toward this limit, including integration/service calls. When the limit is reached, new connections are blocked and the integration receives a 400 error.

How to Troubleshoot

1. Check Active Sessions

  1. Open Business Central / NAV.
  2. Go to AdministrationSessions (or search Sessions).
  3. Review the list for:
    • Idle/inactive sessions
    • Service or integration sessions stuck open

2. Free Up a Session

  • Select unnecessary or idle sessions.
  • Choose End Session to release the slot.
Note: Ending sessions will disconnect that user or service. Make sure this is acceptable.

Alternative Immediate Fix

Restart the BC/NAV Service Tier to clear stale sessions.

  • This will temporarily disconnect all users and integrations.
  • Use only if sessions cannot be safely cleared individually.