I am using a Bluepill board and everything was fine. Then I find I am unable to program, the ST-Link will also work even when the boot 0, boot 1 are in the 0,0 position. A new board had the same problem.

[Tesla DeLorean]

That all sounds rather awkward.

Please try to use a simpler title/summary, and keep the question in the body of the post.

So does the ST-LINK connect, or not?

What exactly do the errors say?

What applications are you using? STM32 Cube Programmer?

Is the NRST pin connected to the ST-LINK? This tends to be a prerequisite to "Connect Under Reset"

The board is not on a conductive surface?

Did you short anything out on the board? Anything else connected?

What were you doing around the time it stopped working/

[Uwe Bonnes]

Real STM F103 or clones?

[HNorr.1]

I bought a second board which was running a flashing LED program. As soon as I programmed it using STM32 cube it stopped working, and the boot pins do not appear to make any difference. The program is being loaded into the STM32 as verified using STM programmer. I think the STM F103 could be clones. Thanks for the replies.

[HNorr.1]

When I run debug it hangs up in HardFault_Handler.