Sometimes there is a conflict between Scratch and the way Windows automatically connects to a bluetooth device that your computer has connected to before.  To get around it, you have to manually tell your operating system to "forget" the device. 

To "forget" the device: 

  • Open settings by opening the Windows menu and choosing Settings (the Gear Icon).  
  • Choose "Devices."  
  • In the list of device "Other Devices" click on your device and then click "Remove Device." 


That should make the device discoverable by Scratch using Scratch Link.