WebGL build doesn't work

I’ve been trying to create a shareable WebGL build of my projects, but I’ve run into several issues. I installed the WebGL 5.5.2 module, but when I try to create a build using the Build button, it has me select a folder, then it either (a) opens the folder I selected, but no new files were created or (b) brings up a “Building Player” progress bar, but gets stuck on “Converting managed assemblies to C++”. If I try the “Build and run” button, it opens a browser tab to localhost that just says “404 Not found.”

As a workaround, I tried creating a git repository for the project so I could use cloud build, but when I try to clone or create a repository using GitHub Desktop, it fails with the error “Couldn’t open /dev/null: No such file or directory”

Anyone know what’s going on with any of this? I haven’t been able to search for a solutions, so it seems like I’ve gotten two separate, obscure issues stopping me from doing this.