Perform the following steps:
1. Login to the project with an user belonging to any of the following groups:
- TDAdmin Group. Users from the TDAdmin group have the permission to cancel the check out of a versioned entity that was checked out by another user.
- Custom group, for which is enabled the group permission in Administration tab -> "Undo Check Outs'.
2. Go to the test and perform the operation ‘Undo Check-Out’.
That will reset the test (entity) in status Check-in and will preserve its history before the last check-out.