Since we got our new error reporting online, we've noticed this message cropping up
Your changes couldn't be saved because the model uses an old version of the renderer. Please go the editor(link) and save the settings to fix this.
It comes up for shading and background both. Going to the edit page as it suggests, it seems the model defaults to PBR as its renderer. Since it only comes up sometimes we figured this wasn't an intentional API change. Any ideas how we could make this behavior work more consistently? Thanks.