Fortnite directx 12?

I have it on Fortnite directx12 and since then I have textures that don't load because it says it is in beta so it is not my PC and it meets the minimum requirements

(I3 8100, gtx 1060 6gb and 16gb 2400mhz ram)

It's best to make sure that your Nvidia drivers are up to date. Best for Directx12, you should also make all graphics settings to the lowest, because then it works best. If there are still problems afterwards, you should switch back to Directx11.