We're continually working on making the Marty scanning tools more robust, but while we're doing that there are other ways to get your Marty connected
If you have done the WiFi setup, and Marty is connected to your WiFi (so there's no “Marty Setup” network any more), then here's a video showing how you can find Marty's IP address directly, and use that in calibration tool or Scratch.
If you haven't set up Marty's WiFi, or think the setup might not have worked correctly, please see this guide
How to find Marty's IP Address
Quick overview
In case you don't like watching videos - here are the basics:
Hopefully that helps. We're working on making the scanner detect Marty automatically more reliably, but in the mean time you should still be able to use your Marty!