PrF UG projects revert project
From Protege Wiki
Reverting to an Archived Version of a Project
You can revert to any archived version of your project.
Select Project | Revert to a Previous Version or click the Revert to a Previous Version button at the top of the Protege window.
All archived versions are displayed in the Revert to Archived Version dialog:
Select the version you wish to revert to. If you wish, you can select to archive the current version before reverting.
Click OK.