STM32F746NG Discovery Kit board throws a DEV_TARGET_CMD_ERR when connecting to STM32Cube

[VGuna.1]

The logs are below:

17:32:34 : ST-LINK error (DEV_CONNECT_ERR)

17:32:34 : ST-LINK SN : 066CFF545057717867203340

17:32:34 : ST-LINK FW : V2J35M26

17:32:34 : Voltage : 3.21V

17:32:34 : Error: ST-LINK error (DEV_TARGET_CMD_ERR)

I attempted flashing the MCU on the dev kit using command line commands (mbed compile...) and I flashed a blink LED program. Since then, I've not been able to connect to STM32 cube to erase/reprogram the device. How do I recover the dev kit?

Thank you!