Hello I found out the problem at least for me. Maybe it will help someone in the future who hasn't found out the problem yet. I had a similar situation with the walls and floor always changing texture like in picture posted by jim_uk. This ocured after installin NCM Large packet files (my first mod, so no conflict with other mods). What I did was install Ojo Bueno and have it override the NCM files ("yes to all" when using NMM). But I was not done yet, because the glitch persisted. What I had to do was to disable the NCM files and re-enable them. When it said that some NCM files where already installed by Ojo Bueno and to replace them I checked "No to all". This fixed my problem after doing it in the order mentioned.