How to add an SSL Certificate to a Unifi Controller when hosted on a Windows instance:

1. Download a program called Keystore Explorer from here > https://keystore-explorer.org/
2. Open the existing keystore (C:\<PATH TO YOUR INSTALLATION LOCATION>\Ubiquiti UniFi\data\keystore) with password “aircontrolenterprise”
3. Tools > Import Key Pair
4. Select the key type use PKCS #12
5. Choose the PFX file and enter the password.
6. Use “aircontrolenterprise” for the key pair password when requested.
7. Choose File, Save As and name the file unifi.  Since Version 8.1.113 if the file isn’t name unifi the site won’t load via SSL
8. Set the keystore password to “aircontrolenterprise”
9. Save file as “keystore”
10. Set keystore file as read-only
11. Restart the service (if you are running the controller as a service) or application

If for some reason the existing keystone is giving you issues you can create a new one by adding the following line to your system.properties file and restarting the service:  “app.keystore.pass=aircontrolenterprise” (without “”)