Why does my flight simulator freeze or hang while loading?

A flight simulator usually freezes while loading because it is scanning a faulty add-on, waiting for inaccessible scenery or online data, rebuilding a cache, or exhausting memory. First establish whether it is genuinely hung, then test a stock aircraft and airport with all third-party content disabled. That split identifies most causes without reinstalling.

This general diagnosis applies to Microsoft Flight Simulator 2020 and 2024, X-Plane, FSX, Prepar3D and other simulators, although their add-on and cache locations differ.

How can I tell whether loading is frozen or just slow?

A loader is genuinely hung when it repeatedly stops at the same stage and the process shows no meaningful CPU, disk or network activity; a Not responding label by itself is not proof. Windows may show that message while a simulator compiles shaders, indexes scenery or scans packages.

The first launch after a simulator update, graphics-driver change or large scenery installation can take much longer than normal. Avoid ending the process while package updates or disk activity are continuing, because interrupting a write can create another damaged file.

What should I disable first?

Disable third-party content before changing drivers, deleting configuration files or reinstalling the simulator. Add-ons are the most common cause of a repeatable loading hang, particularly after the core simulator has been updated.

1. Record the failing setup. Note the aircraft, departure airport, weather source and the last visible loading stage. Preserve add-on lists and back up configuration files before changing them.
2. Create a clean add-on state. In Microsoft Flight Simulator on PC, temporarily move the contents of the Community folder elsewhere and remove any add-on-linker junctions. In X-Plane, move third-party plugins and custom scenery out of their active folders. For FSX and Prepar3D, disable third-party scenery and start-up modules using their supported controls or backed-up configuration files.
3. Run a stock baseline. Select a locally available default aircraft, a stock airport, clear preset weather and minimal AI traffic. If the simulator requires an online sign-in, remain signed in but turn off optional live weather, multiplayer and traffic separately.
4. Restore content in groups. Add half the disabled items back and retest. Continue halving the suspect group until one aircraft, scenery package, plugin or dependency remains.
5. Confirm the diagnosis. Remove that item, restore everything else and repeat the original flight. If the hang disappears, update or reinstall only the identified add-on.

Console editions do not expose PC add-on folders. Disable or remove optional packages through the simulator's content-management interface, perform a full restart rather than resuming a suspended session, and then test stock content.

Why does it hang at the same point every time?

A repeatable stopping point usually identifies the type of content being loaded, although progress bars are not linear and the same percentage does not mean the same component on every computer.

• One airport only: suspect airport scenery, an overlapping regional package, terrain data or a missing library dependency.
• One aircraft only: suspect the aircraft package, its gauges, avionics, livery or required base model.
• Every flight after an update: remove outdated add-ons first, then verify that all core and optional simulator packages completed their updates.
• Online flights only: test live weather, traffic, multiplayer and streamed scenery separately. A stalled service request can resemble a local freeze.
• Random points in complex flights: check RAM, graphics memory and disk use. Older 32-bit simulators such as FSX can exhaust their address space even when the computer has spare physical RAM.

If Microsoft Flight Simulator never reaches its menu, use our MSFS start-up checks for Safe Mode, storage and package scanning. If the menu works but a selected flight stalls, follow the separate MSFS checks for aircraft, scenery and streamed data.

For FSX, a missing scenery drive, damaged default flight or blocked start-up module can hold the loader. Our FSX checklist for scenery libraries, modules and saved flights covers those specific faults. Heavy aircraft and scenery may instead require the steps for reducing FSX out-of-memory failures.

Logs can narrow the search. X-Plane's Log.txt, simulator package logs where provided, and operating-system reliability records may show the last plugin or asset requested. Treat the final entry as a clue rather than proof: it may be the last successful load, while the next unrecorded item caused the stall.

Should I delete caches or reinstall the simulator?

No; clear caches and reinstall only after testing a clean add-on state, because neither action fixes an incompatible aircraft, scenery package or plugin that is restored afterwards.

1. Complete pending updates. Restart the simulator, its launcher or platform client and the computer. Check that core packages and separately managed aircraft or scenery finished installing.
2. Check every storage path. Confirm that internal and external drives are connected, writable and have free space. Disable scenery-library entries that point to removed drives, unavailable network shares or renamed folders.
3. Clear only documented caches. Prefer the simulator's own control for rolling, scenery or shader caches. Back up configuration files before regenerating them, and expect the next load to be slower while data is rebuilt. Do not delete package folders as though they were caches.
4. Verify core files. Use the platform's verify or repair function where available. Read its warning first, because some reset options can remove local settings or downloaded content.
5. Test the clean computer state. Return CPU, GPU and memory tuning to defaults, close overlays and hardware-monitoring utilities, use a stable graphics driver, and leave the operating-system page file enabled. Review security-software quarantine records; create a narrow exclusion for trusted simulator folders only if scanning is proven to be the cause.
6. Reinstall last. Remove or quarantine the old third-party content and configuration before the first test launch. Reusing the same damaged package or configuration can make a fresh installation hang in exactly the same place.