I'm actually working with a LoRaWAN kit (AcSIP LoRaWAN EVK S76SXB) based on STM32L073x and Semtech SX1276 radio module.
So the kit comes with examples based on Semtech example. I have been able to flash thoses examples via SWD pins and an STM32F0 Discovery ST-Link.
But since yesterday, I can't flash anything on the kit. I'm using Keil uVision5. When I try to flash something I get the error message "No target connected". I can't even connect with the ST-Link Utility and when I try to set Boot0 High and use STM32 Flash Loader the program crash right after selecting the COM port when I need to select the device in the target list.
ST-Link is not the problem as I can still flash on the Discovery board.
I'm really out of idea, I don't know if the MCU is bricked or anything else.
If you have any idea, please tell me beacause I'm totaly stuck at the moment.
EDIT : Last time I was able to flash, I tried to change the LoRaWAN region (transmission frequency from ASIA 923 to US 915). I don't remenber if the problem occured right after this change or if I was able to flash one or two more times after that.