How do i fix my materials?

Why do my material have black glitchy areas on the surface, this happened when I updated my Mac OS to High Sierra 10.13.2 so I

would really appreciate if anyone has a solution to this problem.

Go to Project setting, Render tab, then switch, check the screenshot as I already marked to u

may i ask how do i switch between i am a newbie when it comes to this kind of stuff.
Thankyou Trollolled

So when I went to the project settings and ticked forward shading on forward render it told me to restart the project which I did but now I can’t seem to load the project as it is just stuck on 35%.

223897-screen-shot-2017-12-15-at-145222.png

its not stuck, it has to recompile the shaders, give it a while depending on ur hardware.

not specialist with Mac, but it may be forward or deffered render issue, try switching between both and see if that can make any difference.

no problem at all, I’m glad to help, I just switched this to be an answer instead of comment

Hey, Omar I really have to thank you for your time and expertise for helping me it finally finished compiling the shaders of my other projects and now the black glitches are gone for good.
Much appreciated and thank you again Trolloolled