Failed to parse 1 export - Windrose R5BuildingItem (UE 5.6.1, schema index 49 in RTCollisionApproximation)

[DeveloperBlue]

Describe the bug

Opening a cooked building-item DataAsset for the game Windrose shows "Failed to parse 1 export!". The export falls back to RawExport and cannot be edited in the property grid.

UAssetAPI also reproduces the failure outside the GUI:
FormatException: Failed to find a valid property for schema index 49 in the class R5CollisionApproximation

The .usmap (generated via UE4SS on the same game build) only defines 3 properties for R5CollisionApproximation (indices 0–2: ElementsTree, bIsBuilt, ElementRadius), but the cooked asset references schema index 49 while parsing the nested CollisionApproximation struct on R5BuildingItem (property index 58 in the class schema).

Game / engine

• Game: Windrose
• Engine: UE 5.6.1 (cooked IoStore)
• In-game asset path: /Game/Gameplay/Building/BuildingFarming/DA_BI_Farming_Flax_T02
• Export class: R5BuildingItem (DataAsset, 1 export, 506-byte .uexp)

Reproduction

All files are in the attached zip — pre-extracted .uasset/.uexp + .usmap.

1. Unzip
2. UAssetGUI → UE 5.6 → Mappings → included R5-5.6.1-0+UE5-7f7cc36f.usmap
3. Open flax/DA_BI_Farming_Flax_T02.uasset (.uexp must stay beside it)

Expected: editable property tree
Actual: Failed to parse 1 export!

CLI equivalent:
UAssetGUI tojson flax\DA_BI_Farming_Flax_T02.uasset out.json 5.6 R5-5.6.1-0+UE5-7f7cc36f.usmap

Expected behavior

Export deserializes as a normal property tree (NormalExport) so properties such as FastConstructionDirections can be viewed/edited.

Actual behavior

• UAssetGUI: "Failed to parse 1 export!"
• Export type: RawExport (506 opaque bytes)
• Parse aborts on R5CollisionApproximation schema index 49 (see above)

What I've already tried

• Fresh UE4SS .usmap re-dump
• Asking an LLM to investigate it further for me :(

Attachments

Windrose-flax-parse-repro.zip

Contains:

• DA_BI_Farming_Flax_T02.uasset + .uexp
• R5-5.6.1-0+UE5-7f7cc36f.usmap (fresh UE4SS dump)
• (optional) DA_BI_Farming_Soil_BEB_A.uasset + .uexp — 2 exports; main export also fails parse, but R5BuildingStaticMeshSelector_PlaneTiling sub-export parses

Additional context

• Flax has only one export, so a single parse failure blocks the entire file.
• FastConstructionDirections (schema index 36 on R5BuildingItem) is before the failing CollisionApproximation struct — interested in whether partial/unblocking parse is possible when a late nested struct fails.
• Similar open reports: Failed to parse 1 export! #199 (UE 5.6.1), Failed to parse 1 exports on experimental build #211, Failed to parse exports in BL4. (UE 5.5) #212, Failed to parse 3 exports! #213 — this case has a specific schema-index mismatch on R5CollisionApproximation.