SDK Version: 1.7.2
Blender version: 4.5.7LTS
Frequency: Consistently
Severity: Blocker
Since updating to the SU6 Beta and the latest SDK, I am experiencing inconsistent behavior when updating a custom ModelLib object exported from Blender 4.5.7 using the current MSFS 2024 Blender exporter.
The model can initially be exported, compiled and loaded correctly into the simulator. However, after making changes to the model or its materials in Blender, re-exporting it and rebuilding the package, the existing scenery object can suddenly become unavailable in the Scenery Editor.
The Scenery Editor then reports:
Model not found
When trying to place the model again from the Scenery Library, the model may also appear only as a transparent/rotated placeholder bounding box instead of the actual geometry.
The unusual part is that the PackageBuilder reports no errors. The package builds successfully, validates successfully and reports that the assets have been reloaded.
For example:
Validating Package 'nnsd-airport-ehbk-maastricht'...
Validation SUCCESS
PackageBuilder | Reloaded 29 assets
PackageBuilder | Finished, 2 skipped, 36 done and 0 failed
Despite this successful build and reload, the Scenery Editor can immediately report “Model not found” for the same model.
Steps to reproduce
- Create a ModelLib scenery object in Blender 4.5.7.
- Export it using the current MSFS 2024 Blender exporter included with the latest SDK.
- Build the package in DevMode.
- Place the model in the Scenery Editor.
- Confirm that the model loads correctly.
- Return to Blender and make a simple change to the model or its material.
- Export the model again using the same filename, collection and ModelLib location.
- Rebuild the package in DevMode.
- The existing scenery placement may now become unavailable and show “Model not found”, despite the PackageBuilder reporting 0 failed tasks.
Additional observations
Using Clean Package followed by a complete rebuild can sometimes make the model load again. However, after another Blender export and package rebuild, the model may become unavailable again.
During testing I also replaced the existing materials with a very simple material to rule out complex MSFS material configurations. The issue still occurred.
The geometry itself appears to be valid. The same exported model has successfully loaded in the simulator, and a clean package rebuild can make it appear again without modifying the Blender geometry.
This behaviour appears to be related to rebuilding/reloading a ModelLib during a DevMode session rather than to a consistent error in the model itself.
I did not experience this behaviour with the same development workflow in previous simulator updates, including SU5.
Expected result
After re-exporting an existing ModelLib object and rebuilding the package, the Scenery Editor should reload the updated model while preserving the existing scenery placement.
Actual result
The package builds and validates successfully with 0 failed tasks, but the existing object changes to “Model not found”. In some cases, attempting to place the model again results in only a transparent placeholder bounding box.
A Clean Package + full rebuild may temporarily restore the model.
Environment
Microsoft Flight Simulator 2024 – SU6 Beta
Latest SU6 SDK
Blender 4.5.7 LTS
Khronos glTF Blender I/O v4.5.51
Asobo Studio MSFS2024 Blender I/O v7.4.2
Custom ModelLib scenery package
Possible regression
Based on repeated testing, this appears to be a possible regression in the SU6 DevMode/ModelLib asset reload or package hot-reload pipeline.
The most significant symptom is that the PackageBuilder reports a completely successful build and asset reload while the Scenery Editor simultaneously reports that the compiled model cannot be found.
