Cannot Connect to User Agent
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Cannot Connect to User Agent


Article ID: 286658


Updated On:


Carbon Black App Control (formerly Cb Protection)


  • Agent not showing as Connected in Assets > Computers.
  • Agent driver or kernel filter driver is not running
  • Attempting to use dascli commands returns error:
    Cannot connect to user agent.


  • App Control Agent: All Supported Versions
  • Microsoft Windows: All Supported Versions


This message is returned when the Agent service is not currently running. Typically this happens when:

  • Agent service is Stopped, Restarting, or Disabled.
  • Another software program injecting itself into the Agent, and not allowing the service to fully start.
  • The installation has become corrupted.


Typically this can be resolved with a reboot of the endpoint. However, if this does not work:

  1. Verify Antivirus Exclusions for the Agent are in place for any other security product.
  2. Click Start > Run > services.msc > Ok and locate the service, Carbon Black App Control Agent.
  3. Attempt to manually upgrade the Agent to the latest version.
  4. Verify the Startup Type is set to Automatic and verify the status is Running.

Additional Information

  • By default the Agent service has the start type "auto" and the Agent driver has the start type "boot".
  • The following commands in an administrative command prompt will set the Driver and Service accordingly:
    sc config parity start= auto
    sc config paritydriver start= boot
  • The following administrative Windows commands can be used:
    Verify service status: sc query parity
    Verify driver status: sc query paritydriver
    Verify paritydriver is loaded: fltmc
    Verify paritydriver instances: fltmc instances