Port 8080 is not usable

[nilansaha]

Is there something happening with port 8080 with this extension? Because I usually have a backend service running on that port and it says "Upgrade Required" whenever I run it along with the development build of the extension in Chrome.

Is there any way to make the extension use some other port for this development stuff?

[iceniveth]

I have no process running on port 8080 but still getting this error: