Steps to reproduce:

1. Click on create host
2. Fill in Host name
3. Choose SNMPv3 in authpriv mode and fill in the IP address of the server
4. Set Authentication Protocol to SHA 1
5. Type the authentication passphrase
6. Set the Privacy Protocol to AES 256
7. Type the privacy passphrase
8. Add a template and click on update

Result:
Getting a error message stating Unsupported privacy protocol [3]