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
Insert a CmCard containing all licenses required by the project in the controller.
Verified technical data. Last updated: March 2026
Related Faults
Source: Logix 5000