Hey rrr1206,
These referencing errors usually occur if you have upgraded a project or migrated content. Try renaming you project to something different if you upgraded it from a previous version. You can also right click on your ‘Content’ folder within the content browser and fix up redirectors. Make sure all the textures it is saying is missing, are in fact there and not missing. This is not an engine bug, but expected errors and warnings with bad references. Head to our documentation to learn more.
Cheers,