dast

It seems Corona Render is creating a default material for their internal usage, and set the hide-flag in order to hide that material to the public. The Search Material plugin however does its thing by hiding or showing all known materials that matches the required "search"-string. One solution would be to modify the plugin to skip that internal Corona Render material in any of its search actions. But as it is simply named "Mat" that is quite error-prone, as that would skip any default material being created by everyone. The same issue of such "hidden materials" may be present for other 3rd party render engines, or alike. These would also need to be skipped for every search action. I will think about it, and see if I can find a workaround ...

Glad the issue got resolved. And many thanks for the feedback. I really do appreciate the follow up response.

That is weird. The plugin retrieves all available materials from the scene, and only changes the flag to show or hide material.ChangeNBit(c4d.NBIT_OHIDE, showorhide) Nowhere in the code does it actually create any material.