Why is FlightGear not loading, and how do I fix it?

FlightGear usually fails to load because its saved settings are corrupt, a custom aircraft or scenery path is invalid, scenery is still downloading, or the graphics driver cannot create an OpenGL window. Start with a bundled aircraft and installed airport, remove add-ons, reset the user configuration, then inspect the startup log.

What should I try first when FlightGear will not start?

Use a clean, bundled setup before changing or reinstalling anything. This separates a broken FlightGear installation from a problem caused by downloaded content or saved options.

1. Identify where it stops. If the launcher never appears, concentrate on the installation, operating-system permissions and launcher configuration. If the launcher opens but the simulator fails after selecting Fly, aircraft, scenery, saved settings and graphics become the main suspects.
2. Check whether it is still working. Initial scenery downloads and cache building can make the loading screen appear frozen. Watch the log, disk activity and network activity; if the log continues advancing, let it finish rather than repeatedly terminating it.
3. Load a clean test flight. Select a bundled aircraft and an airport whose scenery is already installed. Temporarily disable custom aircraft, custom scenery, automatic scenery downloading, weather downloads and manually added startup arguments.
4. Remove path overrides. Clear custom aircraft, scenery and add-on paths from the launcher. A stale FG_ROOT or a path pointing at an old FlightGear release can prevent even bundled files from loading.
5. Reset saved settings. Close FlightGear and rename autosave.xml in its per-user data folder, normally identified as FG_HOME in the log. FlightGear will create a fresh file on the next start.
6. Check the graphics driver. A black window or immediate exit often means FlightGear could not create a suitable OpenGL context. Install the appropriate graphics driver, remove renderer overrides and test outside a remote-desktop session.
7. Repair the installation last. Reinstall using a known-good FlightGear installer or platform package. Do not combine the executable or base data from different releases.

Do not disable security software globally. If it quarantined part of FlightGear, review the reported file and reinstall the trusted package instead.

What does the loading symptom tell you?

The point at which loading stops usually identifies the failing component. This is more useful than repeatedly reinstalling without checking the log.

Open the launcher's log or output view where available; otherwise start FlightGear from a terminal. Work upwards from the end and find the first specific error, rather than relying on the final generic shutdown line.

• An error mentioning FG_ROOT or missing base files points to an installation or path mismatch.
• An aircraft, XML or Nasal error naming an add-on path usually identifies the faulty aircraft or script.
• Scenery, terrain, object or permission errors point to the scenery path or its cache.
• OpenGL, shader, renderer or graphics-context errors point to the GPU driver or graphics configuration.

Why does FlightGear hang while loading scenery?

A scenery hang is usually a bad path, an incomplete extraction, an inaccessible cache or a location FlightGear is still trying to download. External drives, network folders and sandboxed Linux packages can also lose access to scenery that worked under a different installation.

Test at an airport with known installed scenery, remove every custom scenery path, and temporarily stop automatic scenery downloads. If that works, restore one scenery source at a time. A mistake we see constantly is selecting the folder above or below the directory level FlightGear expects; our detailed FlightGear scenery-path and extraction checks cover that problem without requiring a full reinstall.

If FlightGear loads after custom scenery is removed, the simulator itself is working. Re-extract the suspect package, verify that it is compatible with the installed FlightGear release, and check the log for the first object, model or XML file named before the failure.

How do I reset FlightGear without removing add-ons?

Resetting autosave.xml clears persistent simulator properties without deleting the FlightGear installation. It is the safest reset when FlightGear previously worked but stopped loading after a setting, renderer or aircraft change.

1. Close every FlightGear process. Make sure both the simulator and launcher have stopped.
2. Find FG_HOME. Its location varies by operating system and package type, so use the path printed near the start of the FlightGear log rather than relying on an old folder guide.
3. Back up the file. Rename autosave.xml to autosave.xml.old; do not delete it until the clean configuration has been tested.
4. Start a bundled flight. Leave custom paths and additional arguments disabled for this test.
5. Restore settings gradually. Change controls, graphics and add-on paths in small groups so the failing option is obvious if the problem returns.

If autosave.xml makes no difference, back up the whole per-user FlightGear folder and temporarily move it aside so the program can create a clean one. This can hide packages or caches stored inside that folder, but moving it rather than deleting it keeps them recoverable.

A reinstall alone may not solve FlightGear not loading because uninstallers often preserve per-user settings. If a clean configuration, bundled aircraft and installed airport still fail, the remaining causes are usually a damaged package, mismatched base data, an operating-system permission problem or the graphics driver.