Hi friends.
I have a blue pill discovery board (STM32F103C8) which I programmed several times but now I face with this error message.
I made CubeMX file which create a file in Keil and I write code in it.
I understood when I made CubeMX file, I forgot to select serial wire for programming microcontroller.
Now I can not program and I tried it by reset key in board.
Anyone can help me?