New User Help!

I’m a newbie and need some help please.
When attempting to run a project I get the message “The debug application cannot connect back to the Xojo IDE. This is most likely due to a software firewall or packet filter not allowing localhost network traffic on ports 13897 or 60554. You should reconfigure your software firewall or packet filter to allow the debug application to connect to Xojo”
The Windows Defender firewall is disabled and I am using the free version of Avast

I’d say disable avast as well.

You can check the port the webapp is running on


Once selecting Shared under the Build Settings


You can change the Port the WebApp runs on (Build->Port) and the DebugPort (Debug->Debug Port)

If you want to access them outside the computer/VM you’re running them on then you have to open the ports on the firewall. Otherwise, go to your browser and go to “” for Debug and “” for Built

This error would not be particular to a web app.

At the very least, you’ll need to whitelist Xojo. It’s not uncommon to get false positives in virus/malware programs on Windows.