how to tell if a mod is broken

my game is falling apart and no textures i have been told to fix it by deleting a broken mod how can i tell if a mod is broken

 

I usually start by looking at what textures are being affected (for example, if it's the D-Series, it could be a mod that has something to do with the D-Series or adds something on to it.) And then if I can't immediately tell, I go through my mods, deactivating a mod one at a time and seeing if that fixes the issue. Also remember to clear and deep clear your cache if the problems continue.