Fix an MSVCR80.dll crash in FSX by resetting Logbook.BIN, isolating add-ons and repairing the correct Visual C++ 2005 runtime.
An MSVCR80.dll crash in FSX or FSX: Steam Edition usually means corrupt simulator data or an add-on has failed inside the Visual C++ 2005 runtime; replacing the DLL itself is rarely the fix. Rename Logbook.BIN first, then isolate add-ons, rebuild FSX’s configuration and repair the x86 runtime.
Choose the fix from the crash pattern
The point at which FSX crashes is more useful than the DLL name alone.
| When FSX crashes | Most likely area to check first |
|---|---|
| When opening the logbook, ending a flight or recording flight details | Corrupt Logbook.BIN |
| While loading one aircraft or using one panel | An add-on gauge or module |
| At launch with a side-by-side configuration message | Visual C++ 2005 x86 runtime |
| After changing settings or making a saved add-on flight the default | fsx.CFG or the startup flight |
| Randomly with several aircraft | A broader FSX, driver, scenery or memory problem |
Fixing the MSVCR80.dll crash step by step
Work through these fixes in order and test FSX after each change, so you know which component caused the crash.
- Back up the files you will change. Preserve the active FSX configuration folder, saved flights and add-on XML files. Our FSX backup checklist for settings, flights and add-ons identifies the important locations.
- Reset the FSX logbook. Close FSX and open your actual
Documents\Flight Simulator X Filesfolder. If Windows redirects Documents into OneDrive, use that redirected location. RenameLogbook.BINtoLogbook.BIN.old, then start FSX. A new blank logbook should be created. If the crash stops, the old file was corrupt; copying it back will normally restore the fault. - Test a completely default flight. Use a default aircraft, airport and weather theme, with complex external utilities closed. If this works, test the aircraft, scenery and utility involved in the original crash one at a time.
- Temporarily disable add-on modules. Open
%APPDATA%\Microsoftand find the configuration folder FSX is actively updating. Most boxed and Steam-only installations useFSX; some side-by-side boxed and Steam installations useFSX-SE. Renamedll.xmlandexe.xml, if present, by adding.oldto each name. Restore them one at a time after testing. - Rebuild the FSX configuration. In that same folder, rename the active configuration file—normally
fsx.CFG, orfsx_se.CFGin some side-by-side Steam installations. FSX creates a clean file at the next launch. This resets graphics, controls and other preferences, so do not delete the backup. - Repair Visual C++ 2005 x86. In Windows Programs and Features or Installed apps, find the Microsoft Visual C++ 2005 Redistributable and choose Change or Repair if that option is available. Otherwise, reinstall the x86 redistributable using the original FSX or affected add-on installer. FSX is a 32-bit program, so it needs the x86 package even on 64-bit Windows. Newer Visual C++ packages do not replace the 2005 runtime, and x86 and x64 editions can coexist.
- Check the FSX update state. A boxed installation should have a consistent service-pack or Acceleration setup. Do not apply boxed FSX service packs to FSX: Steam Edition. If a disc repair has rolled back files, follow the correct boxed-FSX service-pack order.
Why does FSX blame MSVCR80.dll?
MSVCR80.dll is part of the Visual C++ 2005 runtime used by FSX and many older gauges and modules. Its appearance as the faulting module does not prove that the DLL is damaged; an add-on can pass invalid data to the runtime and cause the failure there.
Open Windows Event Viewer and inspect Windows Logs, then Application, at the crash time. An accompanying SideBySide event points towards a damaged or missing runtime assembly; our FSX side-by-side runtime repair instructions cover that case. An Application Error tied to one aircraft or module points back to the add-on instead.
What if only one FSX aircraft crashes?
A crash tied to one aircraft usually requires repairing that aircraft rather than Windows. Confirm that the installer is intended for your exact simulator edition, remove any older version as its instructions require, and reinstall it without copying gauges from another package.
If the aircraft works after dll.xml is disabled, restore the file and enable its modules individually. This identifies the failing module without sacrificing every other add-on.
Should I download a replacement MSVCR80.dll?
No; do not download a loose DLL, copy it into the FSX directory or attempt to register it with regsvr32. The Visual C++ 2005 runtime uses manifests and side-by-side assemblies, so an arbitrary DLL can introduce a version mismatch while leaving the real fault untouched.
What if FSX still crashes after these fixes?
Use the Event Viewer faulting module, exception code and exact trigger to continue the diagnosis. If the crash occurs across default aircraft and clean configuration files, follow our structured FSX faulting-module and add-on isolation process rather than repeatedly reinstalling the same runtime.