Download the launcher

Java JAR launcher

Prefer a portable .jar? It updates the client and cache the same way as the Windows EXE. It does not add a desktop shortcut or pin itself to the taskbar. You need a desktop Java runtime to open the launcher window. The game itself still uses a Java 11 runtime that the launcher downloads automatically.

Install Java

Use a 64-bit JDK or JRE that includes a desktop UI (not a headless-only package). Eclipse Temurin is the recommended build.

• Latest LTS (Java 25): adoptium.net Temurin 25
• Previous LTS (Java 21): adoptium.net Temurin 21
• Any current release, all operating systems: adoptium.net/temurin/releases

During setup, enable the option to add Java to your PATH (Windows installer: "Set JAVA_HOME" / "Add to PATH"). Then confirm with java -version.

How to run it

java -jar EtherealLauncher.jar

On Windows you can also double-click the file if .jar files are associated with javaw. On Linux, mark it executable if your file manager needs that, then use the command above.

Troubleshooting

"java is not recognized" or "command not found: java"

Java is not on your PATH. Reinstall Temurin and tick the PATH / JAVA_HOME options, then open a new terminal. On Windows, search Start for "Edit environment variables" and confirm JAVA_HOME points at the JDK folder (the one that contains bin\java.exe).

Double-click does nothing (Windows)

The .jar association is missing or pointed at the wrong program. Run java -jar EtherealLauncher.jar from Command Prompt, or right-click the file, Open with, and choose javaw.exe from your Temurin bin folder.

Unsupported class file version / old Java 8

This launcher runs on Java 8 through current JDKs. If a different jar fails with a class-file error, you are mixing an old client jar with a new JVM, or the other way around. Delete %USERPROFILE%\.ethereal\Launcher\client.jar and let the launcher download a fresh client.

HeadlessException or no window appears (Linux)

You installed a headless JRE. Install a full desktop JDK from Adoptium, or on Debian/Ubuntu add openjdk-21-jre (not -headless).

macOS "cannot be opened because it is from an unidentified developer"

Right-click the jar, choose Open, then Open again. Or run it from Terminal with java -jar after installing Temurin.

Wrong Java is used (several versions installed)

Run where java (Windows) or which -a java (Linux/macOS). Point JAVA_HOME at the Temurin folder and put %JAVA_HOME%\bin first on PATH.

Update failed / missing client.jar

Check your connection, then restart the launcher. The copy button on the error dialog includes the launcher version. Antivirus can also lock downloads under .ethereal\Launcher; add an exclusion and retry.

More detail: Java JAR launcher wiki page.