LegacyVRayShader

[Chules]

Cinema 4d starts some crown models with this message:

Several plugins used in this project are missing.
Saving may result in loss of plugin data
Plugin 'LegacyVRayShader' (ID 1026701)

How can I locate this reference to vray? I don't have vray, I only use corona. But I get this message with some objects. Can I identify the material in some way so I can delete it?

[TomG]

Where do these "Corona objects" come from?

[Chules]

Some old vray stuff converted to corona.
I don't know how to locate the material that channel has, because there are several models and materials that I have in the scene. Is there a method in cinema 4d to locate it?