UE 4.14.3 Crash on Startup? Missing Shader Cache?

Last night I was working on a landscape material in the editor of 4.14.3. Everything was fine (materials setup, naming, etc.) and the game was running in editor. I built the lighting and, right after building completed, the materials were wiped from the landscape and replaced with the default material (checkerboard).

Whenever I opened a material function, instance, or anything related, there were just strings of red text down the preview window. Now I can no longer open the editor, for it crashes every single time.

Keep in mind that I wasn’t doing anything experimental or out of the ordinary; the project hardly had any content in it aside from a master material and a Third Person BluePrint character. In fact, the project was just created the other day.

I’m stumped about this and am not a C++ debugging wiz. I’ve tried deleting the cache folder from the engine contents, but no luck.

I’ve included the error log. Any idea what could be causing this and how to prevent it in the future? Thank you.link text