Prefab preview randomly became red for no reason

Does anyone know why the prefab preview thumbnail of one single prefab makes it look as if it had no model or material, but instead of pink it’s just full red?

It would be a really cool feature if Unity didn’t do this, but instead displayed prefabs the way the look so that users can use the thumbnails to acquire information on the state of the prefab. Such as if they’re missing a material, this would then allow the user to see that the prefab is missing a material. However if some prefabs randomly just go balls to the wall red even though once opened they’re completely normal, the user cannot reliable gain information from looking at thumbnails any more. Maybe Unity can look into this feature for upcoming versions?

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