Out of the blue when I opened my project for the first time today and all the shaders turned like this, I did nothing for it.
I already try to make other materials (since I was using only the default ones), force recompile the shaders, even change my graphics card driver, nothing…
Making clear that I really not change anything, just opened the project one time and this happened.
My theory is that I clicked some hotkey by accident or something, I am new with ue
Looking at the top left on your screen, it seems like you are using the default settings. If you create a completely new project, using the First Person template, does the same issue appear (Everything being white)?