Fix FSX Acceleration fatal errors during installation or launch with the right edition, update order, configuration reset and add-on checks.
To fix FSX Acceleration fatal errors, first confirm that you have boxed FSX rather than Steam Edition, then repair and run the base simulator before installing Acceleration with administrator rights. For crashes after installation, rebuild fsx.cfg, disable third-party start-up modules and identify the faulting module before considering a full reinstall.
Does FSX Acceleration work with Steam Edition?
Do not install the boxed Acceleration expansion over FSX: Steam Edition. Steam Edition already contains the Acceleration aircraft, missions and updated simulator code. The disc installer is intended for boxed FSX and may fail to detect Steam Edition or damage its registration and shared configuration.
If you attempted this, remove only the separately installed Acceleration package if Windows lists it, then verify the FSX files through Steam. Boxed FSX and Steam Edition can coexist, but their add-ons, registry entries and configuration folders must not be treated as interchangeable.
What is the correct FSX Acceleration installation order?
The base boxed simulator must run correctly before Acceleration is added. A mistake we see constantly is installing every available service pack, followed by Acceleration, without checking which updates the expansion already supplies.
- Remove the incomplete installation. If Acceleration appears in Windows' installed-applications list, uninstall it and restart Windows. Do not delete the FSX directory manually.
- Repair or install boxed FSX. Use its original media and install into one consistent location. Acceleration must attach to the registered boxed installation rather than a separate folder.
- Run the base simulator once. Complete any boxed-FSX activation prompt, load a default aircraft at a default airport, start the flight and close FSX normally. If the base simulator already crashes, repair that problem before continuing.
- Use the appropriate update route. For Gold Edition, install and run the base Deluxe component before installing its Acceleration component. Do not add the standalone SP2 package over Acceleration. For other boxed releases, follow the correct boxed FSX service-pack sequence, especially if setup reports that SP1 is required.
- Run Acceleration setup as administrator. Close FSX and background programs first. Do not use Windows XP compatibility mode unless a specific diagnosed problem requires it.
- Test without add-ons. After installation and activation, launch a default flight before restoring aircraft, gauges, scenery or utility modules.
If setup reports unreadable cabinet files, CRC errors or missing installation data, clean the disc and copy its complete contents to a local folder before running setup from that copy. A repeatable error at the same file normally indicates damaged media or an incomplete copy, not an FSX configuration problem.
What do common Acceleration installation errors mean?
| Symptom | Likely cause | First action |
|---|---|---|
| Setup cannot find FSX | Steam Edition, an unregistered boxed installation or damaged registry data | Run or repair the boxed base simulator first |
| Error 1607 or InstallShield failure | InstallShield, permissions or temporary-file problem | Use our steps for repairing FSX InstallShield error 1607 |
| Cabinet, CRC or read error | Damaged media or incomplete copied files | Re-copy the full disc and check the media |
| Product-key or activation failure | Wrong key, wrong edition or an activation-state problem | Follow the boxed FSX and Acceleration activation checks |
Why does FSX crash only after Acceleration is installed?
Acceleration changes the FSX executable and exposes incompatibilities in old gauges, modules and configuration entries. That does not automatically mean Acceleration itself is corrupt.
- Rebuild the main configuration. Open
%APPDATA%\Microsoft\FSXand renamefsx.cfgtofsx.cfg.old. FSX creates a clean file on its next launch. A side-by-side Steam installation may instead use anFSX-SEfolder. - Disable start-up modules. In the same configuration folder, temporarily rename
dll.xmlandexe.xml. This stops third-party modules and utilities from loading without deleting them. - Use default content. Test a default aircraft, default airport, fair weather and no third-party scenery. A crash that returns only with one aircraft or area points to that add-on.
- Restore items individually. Return one XML file, module, aircraft or scenery package at a time until the fatal error reappears.
- Read the faulting-module entry. In Windows Event Viewer, open the Application log and inspect the FSX error. A named third-party DLL is a strong lead. Entries such as
KERNELBASE.dllorntdll.dllusually report where Windows caught the crash, not its original cause.
Do not download loose replacement DLL files or delete Windows' side-by-side SimConnect components. Those actions often create a second fault while leaving the incompatible add-on untouched. If the event entry remains inconclusive, use our full FSX crash-isolation process for modules, damaged files and configuration problems.
Should I reinstall FSX and Acceleration?
A full reinstall is justified only when boxed FSX cannot be repaired, setup cannot detect a valid installation, or default FSX still fails with fresh configuration and all third-party modules disabled. Reinstalling before those checks often reproduces the same fatal error because the incompatible add-on files or roaming configuration remain in place.
Back up saved flights and any original add-on installers first. Uninstall Acceleration before the base boxed simulator, restart Windows, then reinstall in the same clean order: base FSX, first successful default flight and activation, followed by the matching Acceleration media and another default-flight test.