Plugin Registration Tool (PRT) | ‘Invalid plug-in registration stage’ error while unregistering Assembly

While unregistering one of my custom plug-in assemblies from the Plugin Registration Tool (PRT), I got the following error: Invalid plug-in registration stage. Steps can only be modified in stages BeforeMainOperationOutsideTransaction, BeforeMainOperationInsideTransaction, AfterMainOperationInsideTransaction and AfterMainOperationOutsideTransaction. Reason: Fix: If you are looking for downloading and launching Plugin Registration Tool, please refer article here. 🙂