Java JAR launcher

The JAR launcher matches the Windows EXE: it checks version.json, downloads the client and cache, installs a Java 11 runtime for the game, then starts Ethereal. It does not create a desktop shortcut or pin itself to the taskbar.

Download: EtherealLauncher.jar (also listed on the download page).

Install Java

You need a 64-bit desktop JDK or JRE (not a headless package) so the launcher window can open. Eclipse Temurin is the recommended build.

• Latest LTS (Java 25): adoptium.net Temurin 25
• Previous LTS (Java 21): adoptium.net Temurin 21
• All current releases: adoptium.net/temurin/releases

Tick Add to PATH / Set JAVA_HOME during install. Confirm with:

java -version

The launcher itself runs on Java 8 through current JDKs. The game client still needs Java 11 (the launcher downloads that automatically).

Run it

java -jar EtherealLauncher.jar

Windows: double-click works if .jar files open with javaw.exe. Linux: use the command above from a terminal.

Troubleshooting

java is not recognized / command not found
Java is not on PATH. Reinstall Temurin with PATH enabled, then open a new terminal. On Windows, JAVA_HOME should point at the JDK folder that contains bin\java.exe.

Double-click does nothing
The .jar association is wrong. Run java -jar EtherealLauncher.jar from Command Prompt, or Open with javaw.exe from your Temurin bin folder.

HeadlessException / no window (Linux)
You installed a headless JRE. Install a full desktop JDK from Adoptium, or openjdk-21-jre (not -headless) on Debian/Ubuntu.

macOS unidentified developer
Right-click the jar, Open, then Open again. Or run it from Terminal after installing Temurin.

Several Java versions installed
where java (Windows) or which -a java (Linux/macOS). Put Temurin's bin first on PATH.

Update failed / missing client.jar
Restart the launcher. Use Copy on the error dialog. Antivirus can lock files under .ethereal/Launcher; add an exclusion and retry.