Restore action will help you to fix it:
- Click on the Restore action near the stage.
- Confirm the action:
When you point your mouse arrow on the stage, history of all delete/restore actions will be displayed in the pop-up message:
Note: All these actions are applied also to the main stages of pipeline. More information about student stages of pipeline you can find in the following article: What are the stages of pipeline? How many types of stages of pipeline are there?.