The second hotfix to Prepar3D v4.5 ( is now available. It can be downloaded immediately from the Purchased Downloads section of the website.

Conquer the skies in the latest update to v4.5

The Prepar3D v4.5 Hotfix 2 contains numerous new features and improvements. Multiple changes have been made to improve the Virtual Reality (VR) experience including automatically hiding the VR mouse cursor when not in use, providing additional calibration options, and adding the ability to enable eye tracking by default. A new Eye Tracking Demonstration scenario is included that showcases VR eye tracking and guides a new pilot through a representative aircraft startup procedure. Distributed Interactive Simulation (DIS) ground clamping has been completely overhauled bringing enhanced realism to live, virtual, and constructive (LVC) events. Developers now have access to several new Prepar3D Development Kit (PDK) services including advanced VR interfaces that help streamline Mixed Reality (MR) integrations. Additionally, multiple bugs reported by users and developers were fixed, further improving the usability and stability of Prepar3D v4.5.

Only the Client installer is required for the majority of fixes present in Prepar3D v4.5 Hotfix 2. The Content, Scenery, and SDK installers are optional. Each fix listed below is categorized per installer. Please note, you must first have Prepar3D v4 installed to utilize any of the standalone installers (Client, Content, and Scenery).

To install the new Client, you must first uninstall your current Prepar3D v4 Client via Programs and Features in Windows Control Panel.

The Prepar3D v4.5 update may require you to reactivate your product, however if you have an internet connection or have not made any major hardware changes between installations this should not be an issue. For more information please view the Prepar3D v4 Download and Installation Directions.

The newly posted Prepar3D v4.5 ( Full Download on the Purchased Downloads page includes Hotfix 2.

Please be aware that some third party developers might have to update their add-ons to be compatible with this hotfix. Please contact the third party developers directly for any compatibility questions.

Prepar3D v4.5 Hotfix 2

Client Fixes and Improvements

      • Fixed Startup Screen UI issue where the incorrect date would be displayed after loading a scenario.
      • Fixed bug preventing SSAA from being applied on PBR objects.
      • Fixed issue where AI cargo doors would not close before taxi/takeoff in some cases.
      • Fixed issue where AI baggage carts could get stuck in the TAXI state causing AI aircraft to remain in the PreFlight state.
      • Fixed issue preventing pylons without attached weapons from serializing in multiplayer.
      • Tracer rounds now render in multiplayer.
      • VR recalibration origin can now be configured including an option to calibrate with a custom origin without triggering calibration from OpenVR.
      • Fixed crash that could occur when DIS labels were active with high traffic settings.
      • Improved fallback logic when a container title is not found in the DISEntityTypes.xml.
      • Fixed bug where attach points would not animate in some cases.
      • Fixed several positioning bugs with mixed reality portals.
      • Improved portal editing including the ability to modify their PBH and name.
      • Added FOV edit mode for VR controllers.
      • Different shapes can now be used for portals including cylinders, spheres, and rectangles.
      • Gaze detection can now be enabled in VR settings.
      • Fixed crash that could occur when crashing the aircraft while using a Varjo VR-1 headset.
      • Fixed light and text sizing, g-effects, and inverted eye openness values in Varjo VR-1 headsets.
      • Fixed bug preventing 3D airport navigation visuals from drawing in some locations.
      • Fixed crash that could occur during scenario validation if VI sessions were empty.
      • VR mouse cursor is now hidden when not in use.
      • Tooltips are now stored in each pick request.
      • Fixed bug preventing VR tooltips from appearing if other external pick requests were active.
      • Added an AllowLoopback DIS option to allow processing of packets sent by the local machine.
      • Any VR interface can now be enabled on startup.
      • Fixed bug affecting the visibility of attached effects.
      • Added eye panel data to VR settings.
      • Fixed issue causing brightness in HDR to be too low in some cases.
      • Fixed issue where objects with PBR materials would have incorrect vertical positions in some cases.
      • Scaleform panels now serialize local variables (L:Vars) in multiplayer.
      • Added VR passthrough camera settings screen.
      • Fixed issues preventing weapon targets from recording and playing back correctly in some cases.
      • Simplified playback complete dialog text.
      • Entities will now maintain their current course when a PlayFlightRecordingAction completes.
      • Added CIGI auto-start capability.
      • Fixed issue where OnCompleteActions would not fire after AI completed a waypoint list.
      • Improved VR tracker calibration including the ability to use a tracker puck as the camera origin.
      • Fixed bug where add-on airport LLA would not be updated in some cases.
      • DIS pull to ground is now on by default.
      • DIS pull to ground now uses CG height instead of the bounding box for placement.
      • DIS pull to ground transition is now smoothed as well as clamping pitch and bank.
      • Added button to calibrate eye tracking for Varjo VR-1 headsets.
      • Fixed issue where add-on land class textures would not be loaded in some cases.
      • Stereo mode now supported for Vive Pro Eye passthrough camera.
      • Improved handling of alpha values in terrain vector textures.
      • Eye tracking in supported VR headsets is now automatically enabled.
      • Fixed issue where airport runway secondary landing attributes would be ignored and processed as primary landing attributes.
      • Added VR Tuning Guide to the Learning Center.


Content Fixes and Improvements

      • Fixed incorrect fire weapon voice control binding and added default fire gun command.
      • Fixed DIS enumeration for wander boat.
      • Fixed text display, target distance, and target aspect angle issues in the F-16 HMD overlay.
      • Removed the momentum effect from the Virtual Cockpit Only camera.
      • Fixed visibility issues with the explosion flak effect.
      • Added Eye Tracking Demonstration Scenario.
      • Moved F-16 eyepoint forward slightly.
      • Fixed default DIS entity mappings for Lowboy Semi-Tractor Trailer and Tanker Truck Yellow to prevent collisions.


Scenery Fixes and Improvements

      • Fixed incorrect transparency values in several autogen objects.


SDK Fixes and Improvements

    • Fixed incorrect ordering of C-gauge tokens.
    • Fixed variable naming for ISimObject attachment units and updated documentation.
    • Fixed missing GetGeneralTimeOfDay function in the IGlobalDataV430 interface.
    • Custom SimObject properties that override native SimVars now work over SimConnect.
    • Added an OpenGL Panel sample.
    • Updated the picking sample with an example of using world ray interrogation.
    • Fixed a memory leak in the Custom Icon sample.
    • Fixed bug preventing columns from being customized in the Traffic Toolbox tool.
    • Added an Eye Tracking SDK sample.
    • Fixed UV channel optimization issue causing vertex count mismatches in some cases.
    • Added addition simulation categories to SimConnect_RequestDataOnSimObjectType.
    • Added additional VR SDK interfaces.
    • Added world object PDK service to create, place, and remove objects by GUID.
    • Added world object PDK service sample.
    • Added OpenCVStereoCamera PDK sample.
    • Fixed crash that would occur when using the panel system InitializeVarByName function.

Thanks again for your support!