Directional light makes everything white

I have been working on my project in Unity for a couple of weeks without any issue. Last night I opened my project and noticed something weird: when I put in a directional light, every surface of every object becomes pure white; both in the editor and in the rendered image. To confirm its not a project-related issue, I created a new project and put a cube in it, still white. I even re-installed unity and made yet another new project. I'm providing two screenshots, one with the directional light and one with no light objects. What do you think is causing the issue? How can I fix this problem?