20-1

Required license missing or expired

Allen-Bradley · Logix 5000

What does 20-1 mean?

A required license is either missing or has expired during the controller's transition to run or test mode. This prevents the controller from entering an operational state.

Common Causes

  • Required license missing or expired during transition to run or test mode

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Insert a CmCard containing all licenses required by the project in the controller.

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Verified technical data. Last updated: March 2026

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