Looks like you've unloaded a library that had these surfaces, or perhaps migrated an older project to a new version and these textures are no longer in the library. You should be able to select the missing textures in the loading report and get info to see which surface in the project has them missing. You could remove the textures there or replace them with something else if you did migrate to a newer version.
Erwin Edel, Project Lead, Leloup Architecten
www.leloup.nlArchiCAD 9-26NED FULL
Windows 10 Pro
Adobe Design Premium CS5