What server type are you using? PHP, Nodejs, or something else?
I can see the file is an html file, but I am not sure about what type of server.
Edit: Nevermind, I see you tagged nodejs in the post title.
This may be related to a bug that has been previously reported and should have a fix in the next update.
However, in case it is not, please take a screenshot of your server connect action, showing what you have put in for the Security Restrict.