Mathematica generates this message when the license that activates your Lightweight Grid is invalid. Replacing your current license with a valid one fixes the issue.

  • If you use a single-machine license from your Mathematica installation to activate the Lightweight Grid, verify that Mathematica itself runs. If Mathematica does not run, contact Wolfram Customer Support for a valid password.
  • Unsecured or lab passwords cannot be used to activate the Lightweight Grid. If your current installation of Mathematica uses an unsecured or lab password, contact Wolfram Customer Support for a secured password.
  • If you use a MathLM to activate the Lightweight Grid, verify that the MathLM is running. If the MathLM is not running, contact the MathLM administrator.