I'm having trouble with this too. The 10- and 20-pin connectors referenced in the STLINK V3 manual ("ASP-203799-02" and "ASP-203800-02") simply don't exist anywhere. (I'm guessing ST got a custom part number from Samtec for their large volume order...

Thanks mattias for the detailed info! ​That's very helpful to better understand what's going on.

It seemes I stumbled on a solution.​ I went back and selected Project->Build Project​Then Run->Debug As->STM32 MCU C/C++ Application​A new window popped up asking me to make a new debug configuration. I selected 'Okay' without changing anything. ​The...

Same problem! ​I just installed STM32CubeIDE (Windows 10) and tried to blink an LED on a brand new Nucleo-64 board STM32F303RE.​You know, a simple test to make sure everything is working right. Ha well, funny thing is... it's not working. ​I selecte...