A few probable causes for this issue are as follows:
1. When attempting to log in through Security Director, you may encounter an "authentication failed" message as shown below.
2. Please try to reset the super-user credentials by following the KB17582 [juniper.net]
3. Please ensure the disk space is not fully occupied. If the disk space is full, you can follow the KB33025 [juniper.net]
4. If the previous steps appear to be correct, try accessing the main UI
https:// <space_ip> /mainui
5. If the main UI is accessible and applications are either not listed or disabled. Please proceed to Administration >> License to confirm whether the license has expired.
6. If the license has expired, please import and apply the license.
7. Once the license has been successfully applied, all disabled features and applications will be reactivated. After this, logging into Security Director should function properly.