If you manage Ubiquiti networks, you know the struggle. You need the UBNT Discovery Tool to find devices on a Layer 2 network (especially when they have stale IPs or are outside your subnet).
But for years, the tool has come with a major headache: Java.
With the release of Version 2.5.1 and the latest Windows 10 updates, things have changed—for the better and the worse. Here is everything you need to know to get the tool running today.
Go to Settings > Apps > Apps & features and uninstall any old versions of Oracle Java (especially Java 8). They conflict with the bundled runtime.
Introduction The Ubiquiti Discovery Tool (version 2.5.1) is a legacy utility used to discover and initially configure Ubiquiti Networks devices (such as airMAX, UniFi, and EdgeMax products) on a local subnet. Unlike later cross-platform tools, v2.5.1 is a Java-based application. As Windows 10 receives regular cumulative updates (including security patches, .NET Framework updates, and Java environment changes), running this older tool can present compatibility challenges. ubnt discovery tool v251 and java on windows 10 updated
Java Dependency UBNT Discovery Tool v2.5.1 requires Oracle Java Runtime Environment (JRE) 7 or 8 (32-bit or 64-bit, depending on your OS architecture). It is not compatible with:
Common Issues on Updated Windows 10
Recommended Workarounds for Updated Systems
1. Install a Compatible Java Version
2. Launch with Explicit Java Path
Create a batch script (launch_ubnt.bat) in the tool’s folder:
"C:\Program Files\Java\jre1.8.0_202\bin\javaw.exe" -jar UBNTDiscoveryTool.jar
3. Configure Windows Security & Firewall
4. DPI Scaling Fix
Right-click javaw.exe → Properties → Compatibility → Change high DPI settings → Override high DPI scaling behavior performed by: System (Enhanced).
Alternative Approach: Use a Modern Tool Ubiquiti has largely replaced the Java Discovery Tool with: If you manage Ubiquiti networks, you know the struggle
Conclusion While UBNT Discovery Tool v2.5.1 can still function on a fully updated Windows 10 system, it requires manual Java 8 management, security exceptions, and DPI tweaks. For production environments, migrating to Ubiquiti’s current native discovery utilities is strongly recommended to avoid compatibility risks and security vulnerabilities inherent in running legacy Java applications.
Ubiquiti deprecated the Java tool. Download the UBNT Discovery Tool (non-Java) from their community site or use:
First, verify if you have Java installed. Open your Command Prompt (cmd) and type:
java -version