TM4C123GH6PM - Unable to connect to the target device

Hi guys, I'm using CCS Version: 5.5.0.00077 , the CCS cannot connect to my TM4C, please help!

Here is the code I used to test device :

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_types.h"
#include "inc/hw_memmap.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"

int main(void) {
	uint32_t value = 0;
	uint8_t state = 0;
	SysCtlClockSet(
			SYSCTL_SYSDIV_2_5 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ
					| SYSCTL_OSC_MAIN);
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
	GPIOPinTypeGPIOOutput(GPIO_PORTB_BASE, GPIO_PIN_2);
	GPIOPinTypeGPIOInput(GPIO_PORTB_BASE, GPIO_PIN_5 | GPIO_PIN_1);
	GPIOPadConfigSet(GPIO_PORTB_BASE, GPIO_PIN_5 | GPIO_PIN_1, GPIO_STRENGTH_2MA,
			GPIO_PIN_TYPE_STD_WPU);

	while (1) {
		value = GPIOPinRead(GPIO_PORTB_BASE, GPIO_PIN_5 | GPIO_PIN_1);
		if ((value & GPIO_PIN_1) == 0) {
			state ^= 4;
		}
		if ((value & GPIO_PIN_5) == 0) {
			state ^= 4;
		}
		GPIOPinWrite(GPIO_PORTB_BASE, GPIO_PIN_2, state);
		SysCtlDelay(10000000);

	}
}

When I debug, CCS show me this error :

I try to use LM FLash but It cannot get the value of register or MAC Address so  Debug Port Unlock is not worked