I was setting up shaders on optifine, and when I turned them on, the textures for the 3d weapons and blocks became black and purple.

I'm glad it works!

Try restarting after loading the shaderpack

Lol, I restarted after turning on the shader pack a minute ago because my game crashed and turned off the shader pack. I thought I broke the textures but then when I turned the shader pack back on the textures started working. Thanks!