Material doesn't have a texture property?

This error drive me crazy, it happened because while unity was importing a package, something went wrong and unity stop working, after restarting unity this error raised up and the textures and materials in my scene also doesn’t rendered correctly!!
This is the error:

Material doesn’t have a texture property ‘_ShadowMapTexture’

The imported package is Stealth Project.

I believe that this package changes my project setting, so, I uninstalled unity but still nothing happened, so I think it may found some way to return the default settings?

any help please.!!

After many attempts I found a way. In your main project folder you have these folders: Library, Project Setting. these 2 folders are created automatically for you, and they have all your settings and preferences, so, for me I created a new project with unity then I replaced my original Library,Project Settings folder with the new one for the project I just created, and now every thing is just okay, I need of course to make some changes by hand but the main problem (the render thing) is now disappeared and many other warnings are also disappeared.