ac6 cannot debug/program stm32F411RE after update .... yet again.
Hi,
This error message makes me think that the ST-Link is busy (a debug session is already running?). Try to terminate every debug session before running a new one, unplug then replug the ST-Link USB to reload the driver.
Sometimes, if multiple debug session are started on the same target, the OpenOCD executable does not exit well which blocks access for new connection to the ST-Link (You can verify if there is no openocd.exe running in background in the Windows Process Explorer).
Hope it helps,
Kevin
(Ac6)