Also experiencing issues with IFC files directly uploaded to Speckle. The upload works, but the viewer just won’t load.
I used one of the IFC example files directly from BuildingSmart (Duplex_A_20110907.ifc), downloadable here:
There was an issue with one of the objects which is categorized as a Mesh but does not have any geometry data. The viewer now ignores such cases, and the converter will give a warning about the object in question and that it will be ignored.