I started by getting a request to update a page. I went there, and clicked the HTML button. Copied the contents to my clipboard and pasted in a text editor. It was a simple bulleted list, and I modified every link there.
I copied and pasted the contents back to the HTML window. Saved. Saved the page. It gave an error. I don't know what it was. I tried again. Gave an error. Tried again. Checked the page, and it was still showing the errors.
Then I logged out and logged back into the manager and saw that the "web" folder didn't have the reveal arrow. (see attachment)
I tried Firefox (usually use Chrome), same problem. Now I'm getting a 404 on the whole website. I have no idea what's happening.