I figured out what the problem was, or at least, what I thought the problem was. One of the 3rd-party plugins I had enabled was not included in the [project].Build.cs dependencies section. I got build errors in visual studio when I tried to include it. I disabled the plugin in the project manager and now the game works.
Long story short, it was a dependency issue. The log may or may not have pointed that out, but I doubt it because the build would still succeed.