FAQ and Troubleshooting
This guide collects answers to frequently asked questions and troubleshooting advice for resolving common issues with Gens Launcher.
Frequently Asked Questions (FAQ)
Does Gens Launcher support offline accounts?
Yes. While we strongly recommend playing with an official Microsoft account for multiplayer skin support and verified server access, Gens Launcher includes full support for offline profiles on local area networks.
Why does Windows display the blue SmartScreen warning on install?
Gens Launcher is an independent, non-commercial open-source project. Acquiring commercial EV Code Signing certificates costs hundreds of dollars per year. Simply click "More info" and select "Run anyway". The complete codebase is public on GitHub.
Are my Microsoft credentials secure?
Yes, completely. Gens Launcher uses Microsoft's official OAuth2 Device Code Flow. The application never sees or touches your password. Session tokens are encrypted on disk via OS-level security APIs (safeStorage or PBKDF2 with 600,000 iterations and AES-256-GCM).
Is Gens Launcher free?
Yes, 100% free with no ads. The project is licensed under the MIT License and includes zero telemetry or data tracking.
Common Issues and Solutions
1. Game crashes or fails to launch (Java errors)
- Verify your Java version: Minecraft 1.20.5+ requires Java 21 or Java 25. Minecraft 1.18 to 1.20.4 requires Java 17. Minecraft 1.16 requires Java 8.
Open Instance Settings and let Gens Launcher automatically download and assign the appropriate runtime. - Inspect memory allocation (RAM): Allocating less than 2 GB can trigger
java.lang.OutOfMemoryError. Avoid assigning more than half of your total system RAM to leave room for your operating system. - Conflicting mods: Check the instance Logs tab to locate the mod causing the crash (look for
CrashReportorMixinApplyError). Disable the problematic mod using the toggle switch in the Mods tab.
2. Horizon Cloud Sync fails
- Verify Internet connectivity: When offline, the launcher automatically defuses background sync tasks to avoid hanging the UI.
- Active lock message (horizon.lock): If the game crashed unexpectedly or is still active on another machine, an atomic lock protects your files. If you are certain no process is running, unlock the instance via the Purge Lock button in Advanced Settings.
- Cloud token expiration: If your cloud provider revoked permissions, simply disconnect and reconnect the provider in Horizon Settings.
3. macOS installation issues
- "Application cannot be opened because it is from an unidentified developer": Right-click the Gens Launcher icon in
/Applications, choose Open, and confirm by clicking Open again. This prompt only occurs on the first launch.
Getting Help
If you continue experiencing issues:
- Gather your error logs via the Help / Logs menu.
- Open a public ticket on the Gens-Launcher GitHub Issues repository.