This article explains how to list a managed device to install IDP signature database package via Security Director UI

Device is not visible while installing IDP signature database package via Security Director UI

Step 1: Navigate to Security Director > Administration > Signature Database. Then Click on "Install Signatures" and under probe device dropdown select "Full Probe" then "Probe IPS/App Devices" job will triggered to list all the managed devices. Refer below Image for your reference. 



Step 2: Verify that the "Probe IPS/App Devices" job is successful. To verify you can just double click on the job and it will list all the managed devices which is having IDP signature license installed on it.

Step 3: Once the device is listed you can install the IDP signature database package by following KB27825 [juniper.net]