How do I update Prepar3D safely without breaking add-ons?

To update Prepar3D safely, first determine whether it is a point release or a new major version. Back up configuration and add-on registrations, verify every essential add-on, follow the release-specific component instructions, test Prepar3D clean, then re-enable updated add-ons in small groups. Never overwrite the simulator folder manually.

A P3D update should use the installer or component packages supplied for your licensed release. The release notes take precedence over generic advice because some updates replace only the Client, while others require matching Content, Scenery or a complete installation package.

What should I back up before a P3D update?

Back up Prepar3D's configuration, package registrations, user files and any third-party content that cannot be recreated from its installer.

• Record both builds: note the complete version and build number installed, plus the target build. Do not rely on the major version alone.
• Copy the configuration folders: preserve %APPDATA%\Lockheed Martin\Prepar3D vX and %PROGRAMDATA%\Lockheed Martin\Prepar3D vX, where vX represents your major version.
• Preserve Documents data: copy the version-labelled Prepar3D Add-ons and Prepar3D Files folders from your active Documents location. Documents may be redirected to another drive or cloud-synchronised folder.
• Save registrations: retain files such as add-ons.cfg, scenery.cfg, dll.xml and exe.xml where present. Also copy each external package's add-on.xml manifest.
• Record external paths: make a list of aircraft, scenery, weather, traffic and utility packages stored outside the simulator directory.
• Keep installers and activation details: complex aircraft and utilities may need an updated installer or renewed registration after the simulator changes.

Copy these files rather than moving them. A Windows restore point and a copy of the main Prepar3D folder are not complete backups: neither reliably preserves installer records, package registrations, shared components or activation data.

Is this a Prepar3D point release or a major-version upgrade?

Treat a point release as a controlled update of the existing simulator, but treat a move to another major Prepar3D version as a separate installation.

Do not point an old installer at the new simulator or copy the entire Effects, Gauges or SimObjects directories across. A move from v5 to v6, for example, requires product-by-product checking; our v5-to-v6 add-on compatibility breakdown explains which types of add-on present the greatest risk.

Keeping the old major version installed provides a useful reference where your licences, installers and available storage permit it. Establish a working stock simulator first, following our clean Prepar3D installation procedure for PC, before introducing migrated content.

Safe P3D update procedure

The lowest-risk sequence is to isolate third-party software, update only what the release requires and prove that the stock simulator works before restoring anything.

1. Read the release instructions: confirm the target build and whether it requires the Client, Content, Scenery or a full package. Use packages belonging to the same release set; mixing component builds can produce missing assets and unexplained loading errors.
2. Check essential add-ons: verify support for the target build, not merely the same major version. Give priority to complex aircraft, native DLL modules, shader tools, weather engines, traffic software, camera utilities and hardware interfaces.
3. Complete the backup: close Prepar3D and connected programmes before copying files. Confirm that the backup can be opened and that external package paths have been recorded.
4. Disable third-party content: use the simulator's add-on controls or the product's own manager where available. Untick traditional Scenery Library entries and stop external programmes. Do not delete packages or casually edit XML registration files.
5. Install the required components: if the release instructions prescribe component replacement, remove only the named component through Windows Installed apps or Programs and Features, then install its matching replacement. Do not uninstall the entire simulator for a Client-only update. If a same-machine uninstaller offers licence deactivation, retain the activation unless the release instructions explicitly require otherwise.
6. Test a stock flight: start Prepar3D with third-party content disabled, select a stock aircraft and stock airport, then confirm that the flight loads and the menus and controls respond. Avoid a saved flight that references add-on aircraft or scenery. The first start may take longer while generated data is rebuilt.
7. Update add-ons before enabling them: install versions approved for the new build, then introduce them gradually rather than restoring the complete collection at once.

External add-on.xml packages are less likely to be overwritten than files installed directly inside the Prepar3D directory, but they still require compatibility checks. Our guide to external packages, backups and safe add-on management covers disabling and updating them without creating duplicate registrations.

Should I install only the Prepar3D Client?

Install only the Client when the release instructions say that its fixes do not depend on revised Content or Scenery.

• Client: the main executable and core simulator components. Build-specific DLL add-ons are most exposed to Client changes.
• Content: default aircraft, effects and related assets. Replacing it may overwrite modifications made directly to default files.
• Scenery: base scenery and world data. It normally does not need replacing for a Client-only fix unless the release specifically requires it.

Updating fewer components is not safer when the release expects a matching set. Conversely, reinstalling Content or Scenery unnecessarily creates more opportunities to overwrite customised default material.

A correctly applied point update usually leaves external add-on packages in place. Add-ons installed inside the core simulator folder are more vulnerable, and configuration changes can make intact packages appear missing. Before reinstalling a missing product, inspect its package registration and Scenery Library entry; running an installer and manually registering the same package can create duplicates.

Re-enabling add-ons without losing the culprit

Enable add-ons by category, restarting and testing Prepar3D between groups so that any failure has a small set of suspects.

1. Foundational libraries: enable only object libraries or shared packages required by later scenery.
2. Scenery: add one region or airport group at a time and check for duplicate entries, missing objects and loading stalls.
3. Aircraft: test simple aircraft in small groups, but introduce each complex aircraft separately.
4. External programmes: restore weather, traffic, camera and network applications individually.
5. Native modules and shader tools: leave DLL-based and graphics-altering products until last because they are particularly sensitive to Client changes.

Use the same stock test flight after each change, followed by the add-on's normal scenario. If a group causes a failure, disable it and split the group until one package remains. Enabling an entire collection at once removes the quickest route to the culprit.

What if Prepar3D crashes after the update?

Return to a clean stock start first, then separate an incompatible add-on from damaged configuration or an incomplete component update.

1. Disable the last group: confirm whether Prepar3D loads with all third-party packages and connected programmes switched off.
2. Check the crash record: Windows Event Viewer may name a third-party module. A core Prepar3D or Windows module listed as faulting is not conclusive proof that the core file caused the crash.
3. Regenerate the configuration: with Prepar3D closed, rename Prepar3D.cfg and let the simulator create a fresh copy. Reapply settings selectively rather than restoring the old file wholesale.
4. Clear shaders only for graphics faults: if the problem involves black graphics, display corruption or a graphics-related start-up failure, rename the Shaders folder beneath %LOCALAPPDATA%\Lockheed Martin\Prepar3D vX. Prepar3D will rebuild it.
5. Repair the matching component: repair or reinstall only the affected component using files from the target build, then test again without add-ons.

Do not copy an old DLL into the updated installation or restore an entire core-folder backup over the new files. Reinstalling Prepar3D cannot make an incompatible module compatible. For persistent failures, follow our detailed Prepar3D crash-isolation workflow before resorting to a complete uninstall.