run the .bat(windows) or .sh(linux) to re-program your SuRG unit's application, and bootloader.

If having trouble runnintg the .bat script on windows, look at updating the JLink.exe file path in SuRG_Demo.bat,as it might be causing the issue.
Or alternatively, just run the .JLink script directly (double clicking) if you have the JLink application already installed

If you do not have the JLink tools or drivers, you can download them from here: https://www.segger.com/downloads/jlink/