Pink (magenta) textures mean the simulator is reading the add-on's files while they are still protected, so the textures cannot be decoded. This almost always means L3 SimGuard was not running when the simulator loaded the add-on. Try this:

1. Check that L3 SimGuard is running. Look for its icon in the Windows system tray, near the clock. (L3 SimGuard can also start automatically with Microsoft Flight Simulator.)
2. If it is not running, start it, and allow the administrator (UAC) prompt so it can enable protection.
3. Restart the simulator. Once the simulator has already loaded an add-on with pink textures, reloading it in-session will not fix it. You must close and restart Microsoft Flight Simulator (with L3 SimGuard running). The textures will then render correctly.

If textures are still pink, the issue is usually activation or the protection driver not starting. See the activation and start-up questions below.

L3 SimGuard needs to reach our license server to validate your activation. Check:

• Internet connection. A working connection is required for the first activation and periodically afterwards. A purely offline machine cannot activate.
• Activation key. Make sure the key is entered exactly as supplied. If it is reported as invalid or already used, contact the add-on developer to check or reset it.
• Date and time. A badly wrong system clock can break the secure connection. Set Windows to update the time automatically.
• Try again after a short wait. Temporary server or network hiccups usually clear on a retry.

• Allow the administrator prompt. L3 SimGuard needs administrator rights to enable the protection driver, so Windows shows a User Account Control (UAC) prompt at start-up. Choose Yes. Without it, protected content cannot be decoded and you will see pink textures.
• Check your antivirus. Some security software wrongly quarantines or blocks L3SimGuard.exe or its driver. If L3 SimGuard disappears or fails to start, add an exception for it in your antivirus, then start it again.
• Restart Windows if the protection driver still does not load. A reboot clears a driver left in a bad state by a previous crash or update.

L3 SimGuard needs outbound HTTPS access to our license and update servers. On some networks this is blocked, for example by a corporate or school firewall, or in regions with restricted international connectivity.

• If activation fails only on one network, try a different connection, such as a mobile hotspot.
• On a managed network, ask your administrator to allow outbound HTTPS (port 443) to our license and update servers.
• Where international access is restricted, a VPN to a region where the service is reachable may help. Only use a VPN where it is permitted by local law and by your network's policy.

L3 SimGuard is a desktop application from LAND3 Simulations that protects licensed Microsoft Flight Simulator add-ons from unauthorized copying. It decodes a protected add-on's files only while it is running, so the simulator can use them normally.

For licensing it sends a device identifier, your activation key, and license validation timestamps, plus basic software and version information, and optional crash reports you can disable in Settings → General. It does not read or upload the contents of your add-ons or your personal files. Full details are in our Privacy Policy.