Schema validation fails for IFC that opens fully in Revit (possible validator/schema interpretation issue)

### Description

Hello buildingSMART Validate team

We have an IFC file that opens fully and normally in Autodesk Revit (no warnings, no missing elements), but it fails the Schema validation step in the buildingSMART IFC Validation Service.

Revit’s IFC export team reviewed what we shared and suggested this looks like an issue with the validation service itself and should be reported to buildingSMART. (https://github.com/Autodesk/revit-ifc/issues/947)

- Building SMART Validation Service dashboard: https://validate.buildingsmart.org/dashboard

- IFC Schema Validation report:

### Steps to reproduce

In Revit, Link IFC (or Import IFC) using the attached IFC file

Confirm the model opens normally in Revit

Upload the same IFC to the buildingSMART Validation Service:
https://validate.buildingsmart.org/dashboard

Run validation and observe the failure under **Schema validation**

### Expected result

The IFC should pass schema validation (or at least identify specific non-conforming entities/relationships clearly), especially since it opens normally in Revit.

### Actual result

- ✅ Revit: Opens the IFC completely and normally

- ❌ buildingSMART Validation Service: **Fails schema validation**

### Environment

Revit version: Revit 2026

IFC Revit Version : IFC.for.Revit.2026.4.1.0

IFC schema exported: IFC2x3

Export method: [Revit built-in IFC export]

OS: Windows 11

### Attachments

IFC file: https://we.tl/t-0SdwlXw3ql

### Revit Version

2026.4.x

### IFC for Revit Addon Version

26.4.1

### Windows Version

11 22H2