What are MSFS Sim Updates, and how do I install them in MSFS 2024 and 2020?

MSFS Sim Updates are official Microsoft Flight Simulator patches for core code, aircraft, avionics, flight dynamics, performance and stability. To install one, close MSFS, update the game through Steam, the Microsoft Store/Xbox app or your console, then launch it online and complete any required in-simulator package download.

What does an MSFS Sim Update change?

A Sim Update changes the simulator itself rather than concentrating on scenery for a particular country or region. Release names are usually shortened to SU followed by a number, but that number is not the same as the full software build number.

An update can modify the flight model, weather, traffic, default aircraft, avionics, VR, performance, stability, shared data and developer tools. Some streamed or server-side data may change independently without being labelled as a Sim Update.

Microsoft Flight Simulator 2020 and Microsoft Flight Simulator 2024 have separate update branches, so their SU numbers are not comparable. MSFS 2024's named release is Sim Update 5, issued in April 2026. MSFS 2020 remains a separate PC and Xbox product.

A Sim Update does not automatically replace every Marketplace product or manually installed add-on. Those packages can have their own updates and compatibility requirements.

How do I update MSFS 2024 or MSFS 2020?

Install the platform update first, then open Microsoft Flight Simulator and let it download any required simulator packages.

1. Close MSFS completely. On PC, check that it is no longer running in the background. On Xbox, quit the game instead of leaving it suspended in Quick Resume.
2. Install the platform patch. Check Steam, the Microsoft Store/Xbox app or the console's update queue. Do not launch MSFS while the platform still says it is downloading, verifying or patching files.
3. Launch the simulator while online. Sign in with the account that owns or has access to the simulator. Accept the mandatory package download if one appears during start-up.
4. Check the package destination on PC. If MSFS asks for an installation path, make sure it points to your existing Packages location. A wrong or reset path can make the updater propose downloading the whole simulator again.
5. Wait for downloading and installation to finish. The progress display may pause while files are decompressed or replaced. Keep the simulator open while there is continuing network or disk activity.
6. Check owned content separately. Open the simulator's content library, Marketplace or My Library area and install any updates offered for aircraft, airports or scenery.
7. Restart and test a default flight. Use a default aircraft and airport first. If that works, re-enable Community add-ons in small groups.

Where does an MSFS Sim Update start on each platform?

The first stage always comes from the platform that installed the simulator, not from the Community folder or Marketplace.

Why does Microsoft Flight Simulator download the update twice?

Two download stages are normal because the platform application and the simulator's larger content packages are delivered separately.

Steam, the Microsoft Store, Xbox or PlayStation first updates the executable and platform-managed files. After MSFS launches, it may download aircraft, shared assets or other official packages through its own installer. A working Play button therefore does not prove that the entire Sim Update is installed.

On PC, patching may continue with little or no network traffic because the platform is unpacking files and rebuilding archives. Check disk activity before assuming a stationary progress bar has frozen.

How much Sim Update data and free space do I need?

There is no fixed Sim Update download size; it varies by release, platform and the packages already installed.

Check both the platform download queue and any size shown by the in-simulator updater. Those figures can represent different stages and may not include temporary space needed for decompression. MSFS 2024 streams more content than MSFS 2020, but it can still require substantial local space for application updates, cached data and installed packages.

If an update is going to the wrong drive or there is not enough room, use our instructions for changing the MSFS download and package location safely. Do not delete the Official folder at random; doing so can turn a patch into a much larger redownload.

Are Sim Updates the same as World Updates?

Sim Updates change core simulator code and systems, while World Updates primarily add or revise regional scenery.

A Sim Update can be fully installed while World Updates remain pending. Our guide to updating World Updates and official MSFS scenery explains that separate process.

Do I need to install every Sim Update in order?

No. The platform normally supplies the latest cumulative build, so a returning player does not have to locate and install each previous SU separately.

After a long absence, expect a platform update followed by additional simulator and owned-content downloads. If you joined a preview or beta branch, leave that branch before expecting the normal public build; otherwise the platform may continue offering a different version.

In MSFS 2020, a Mandatory Update message means the installed core build no longer matches the version required for normal online use. Exit the simulator and check the platform updater first. Repeatedly reopening MSFS cannot install a missing Steam, Store or Xbox application patch.

How can I tell whether the Sim Update installed correctly?

The update is complete when the platform has no pending MSFS patch, the simulator reaches its main menu without another mandatory-update message, and no required core package remains in the in-simulator installer.

The displayed software build number may not literally contain the SU number. Also, pending aircraft, Marketplace or World Update packages do not necessarily mean the core Sim Update failed. Test with a default aircraft before judging the installation by the behaviour of a third-party add-on.

Why is the MSFS mandatory update missing, looping or stuck?

Missing or repeating updates are usually caused by a stale platform client, the wrong account or installation path, insufficient storage, a preview build or an incompatible add-on.

• No update appears: close MSFS, restart the PC or console, reconnect the platform client and confirm that the account has access to the game. On Microsoft Store installations, check both the Store library and Xbox app.
• The mandatory-update message repeats: the platform application and simulator packages may be on different builds. Follow our focused procedure for fixing the MSFS mandatory-update loop rather than reinstalling unrelated packages.
• MSFS proposes a full download: verify that it has detected the existing Packages location. Do not accept a new empty destination unless you intend to create a separate installation.
• The progress bar stops moving: check network and disk activity. Patching and decompression can continue without visible download traffic; restart only after both have stopped for a sustained period.
• The update runs out of space: clear space on both the platform installation drive and the drive containing simulator packages. Temporary working space may be required in addition to the displayed download size.
• MSFS crashes after the update: temporarily move or rename the Community folder, disable any add-on links and test a default aircraft at a default airport. Our guide to managing Community-folder add-ons explains how those packages are installed and replaced separately.
• You used a beta or preview build: confirm that the device has left the preview programme, restart the platform client and let it replace the preview build with the public release.

A mistake we see constantly is treating every post-update aircraft fault as a broken Sim Update. An empty Community folder and a default flight quickly distinguish a damaged core installation from an add-on that has not yet been made compatible.