OpenOCD STM32F4 Eclipse Debugging Error

Hi. I use;

-STM32F4-DISCOVERY BOARD (with Embedded ST-Link V2)

-Win7 OS

-Eclipse Oxygen IDE

-OpenOCD debugger

I did every configuration about debugging on eclipse with OpenOCD. When I start debugging I get an error; “undefined debug reason 7 - target needs reset”

and “Info : dropped ‘gdb’ connection”

Any idea?