After reaching the support trough email, they gave me this solution that worked for me :
- Quit all running Applications.
- Click on the Finder.
- Click on the Go menu hold down the option key and click on Library when it shows up.
- Reboot the computer just to clear anything that might be hung up.
- Navigate to Mac HD > Library > Application Support > Steinberg
- Delete the Activation Manager folder.
- Open the Application Support > Steinberg.
- Delete the Activation Manager folder
- Install this version : Steinberg Activation Manager | Steinberg
- Create a new admin user on your computer and then switch to that account
- Launch the activation manager from the new admin account and see if it is working.