[Effective downgrading of access to various Resource Content ??]

I have the same issue. Can't access the 3D image prop plant libraries. They appear to be in a folder called 'Plants' in the libraries folder but seems to need Landmark to access them. 

[Issue with texture in 2020]

I am running SP2 and am still having this issue  standard textures with the 'ATTR' suffix - e.g. 'perforated round offset attr RT' or 'Porcelain attr RT'. I had the problem with textures with the 'use object fill' setting but that seems to have been fixed.