Model seems to be valid but renders empty with error logged

[hybridherbst]

Description

A specific model renders empty in model-viewer but displays correctly in other viewers (e.g. three.js editor, Don's old and new viewers, ...).

Live Demo

Drop this model into modelviewer.dev/editor:
plant_3.o.zip

There's an error logged:

space-opera.js:80510 Mesh is missing primitive index association

Browser Affected

• All as far as I can tell

[elalish]

This has come up before, see mrdoob/three.js#25252, which I suppose I should actually contribute. If you happen to figure out what part of the glTF is triggering this bug, please post it here - it may help with that refactor.