To reactivate groups:

1. Check Show inactive groups checkbox to switch the view in the Table of Groups to inactive groups. The Main Controls will change to only one new control Activate, which can be used to activate inactive groups.
2. Select the groups you want to make active. Multiple items can be selected by dragging or holding CTRL or SHIFT while clicking.
3. Click Activate button from the Main Controls.
4. Click Apply to keep changes or - when prompted to save changes on exit - click OK to confirm.

Note: Reactivated groups will be mapped to the same roles as before their last deactivating.