Page tree
Skip to end of metadata
Go to start of metadata


  • You receive the error message:

    • Background service could not be started. Please check Preference > Ports to see if ZCB ports are in use.

What's going on?

ZCB runs three services in the background:

  • ZWCService
  • ZCBService
  • ZWC-Database (ZCB 4.8 or higher) or ZWC-MySQL (ZCB 4.7 and lower)

All three services are essential to ZCB operation. If one or more services cannot start, an error will appear.

ZCB requires access to certain internal ports. If those ports are blocked, ZCB services may fail to start.

Blocked ports are not the only reason the Services may fail to start, just the most common. You can see which ports are in use by which process by running the command netstat -ab from an elevated command prompt.


  1. Verify that the ports required by ZCB are not blocked.
  2. If services still fail to start, check for errors in your Application Event and System Event logs.
    1. In some environments, the Services must have "Log on as a Service" rights. If this is the case, the logon failure will be noted in the Application Event Logs.
  3. If you still need assistance, please collect logs and open a support case.
    1. See Collecting ZCB logs for troubleshooting
    2. Open a support case from the Support tab of the Zmanda Network.