I’m demoing cursor 0.39.0 and attaching any docs in the chat returns the connection failed message. Not a great impression for me at the moment. If you’re charging money for this I’d expect features to work.
There seems to be quite a few recent posts about connection errors.
The first line of troubleshooting seems to be questions around whether you are using any “irregular’ networking setup on your machine, eg StarLink, zscaler or a VPN etc.
I noted one possible solution here and it worked for one user, but not others it seems: