I came back to my computer last night to work a little on my game. When I tried to run my scene, the splash appeared in a window of the proper size, but briefly closed. This error appeared in the output:

I'm not sure if this would be of any help, but this is what appears in the terminal from when I first load the project to when I attempt running it.

Ever since this problem occurred, I haven't been able to work on my project at all. The game won't run. It's been suggested that the bug might have happened because of firewall settings, but I don't recall making any changes to system settings at all. I've given all permissions to all Godot engine programs, and It doesn't seem to have made a difference.
EDIT: I got home and figured out that there were broken dependencies in one of my scenes, but I'm not really sure how to fix that. Here's the repair window. The only apparent option I have is to click "Fix Broken," which does nothing:

Please help. Working on this game is the only way I maintain my sanity.