You deleted your database or recreated your Docker container without persisting the .n8n directory, leading n8n to think it’s a new instance even if it's the same server.
environment: - N8N_LICENSE_AUTO_RENEW=true activation key has already been used on this instance n8n
If you are in a development environment, ensure your docker-compose.yml or environment variables include: You deleted your database or recreated your Docker
If you are running n8n via Docker and you recently recreated your container (e.g., docker-compose down and docker-compose up ), you might have inadvertently created a scenario where the container ID changed, but the data persisted. Using the API method in Scenario 1 is strongly preferred
(Note: This is the "manual hack" method. Using the API method in Scenario 1 is strongly preferred.)
The key was actually accepted on your first try, but a UI glitch or a lack of refresh makes it look like it failed.