Even if Java is installed, the Discovery Tool might not find it.
Because maintaining legacy Java installations on Windows 10 presents a security risk, Ubiquiti has shifted focus. The most "updated" way to use Discovery functionality on Windows 10 without Java headaches is the Ubiquiti Device Discovery Tool Chrome Extension. ubnt discovery tool v251 and java on windows 10 updated
This extension bypasses the need for a standalone JRE by utilizing the Chrome browser's capabilities. Even if Java is installed, the Discovery Tool
The Discovery Tool uses Layer 2 broadcast frames and UDP port 10001. Windows 10’s firewall, especially after the “2023-11 Cumulative Update,” aggressively blocks raw socket access for non-signed Java apps. Click OK on all dialog boxes to save
Fix:
Additionally, ensure your network is set to Private (not Public). Go to Settings → Network & Internet → Ethernet/Wi-Fi → Properties → Network profile → Private.