This was working fine up until yesterday. Now when I connect my Android device for USB Debuggers. Chrome is no longer display my app.
Now the popup window shows HTTP/1.1 404 Not Found.
Looks to be connecting fine and the app runs fine on my Mobile Device.
Solution was to access through chrome://inspect/#devices
Then select the "Fallback" option.
This is because the remote browser was newer than the client browser……