Folks, this error is happening to me when using socket.io: "io is not defined". Already link the CDN socket.io and locally; I have already used and "deprecated" Express and nothing.
The interesting thing is that when I open the source in the browser (CRTL + U) and click on the link of the src file of the client it says that it did not find the socket-io.js file (if you are linking the file locally) >
Has anyone ever been through this?