Immediately after initial install:
Hey, are you using a VPN or any other software that restricts your internet connection?
I must have some problem like that. I am not on a VPN. I do have ESET installed and watching network traffic. It looks like the 404 in the Developer Tools Console is a normal part of the Cursor login process.
The Cursor application attempted to initiate login with my default browser and the browser did not respond. Several hours later the login page opened in my browser (I don’t recall what the Cursor login page looked like but I think it opened with an error message about a timeout).
Anyways after a restart I was able to login, this must be a local problem of mine.
I’m glad you found a solution.