---
title: "LicenseServerUnavailableEvent"
description: "License server is unavailable. VMware vSphere cannot communicate with the license server. Make sure that vCenter Server is powered on and ESX/ESXi hosts can connect to it."
canonical: "https://helpcenter.veeam.com/docs/mp/kb/licenseserverunavailableevent.html"
breadcrumb: "Veeam MP for VMware Online Knowledge Base > vCenter Server Alarms > Veeam VMware: License Error Alarm > LicenseServerUnavailableEvent"
dateModified: "2026-09-10"
---

# LicenseServerUnavailableEvent

## Summary

License server is unavailable.

## Causes

VMware vSphere cannot communicate with the license server.

## Resolution

- Make sure that vCenter Server is powered on and ESX/ESXi hosts can connect to it.
- Make sure that the firewall is not blocking license server ports: 27000 and 27010.

## External

Refer to [VMware Online Documentation](https://docs.vmware.com/en/VMware-vSphere/index.html#com.vmware.vsphere.storage.doc/GUID-52E19C11-32DD-4145-A952-24A4783DBD14.html) for more information.