MSP432P401R: Hardware BSL Invocation doenst work

Part Number:MSP432P401R

Hi,

i add the flashmailbox.c and flashmailbox.h files to my CCS project and i am trying to hardware invoke the BSL on MSP432.

So inside main i place this on the very top:

if(CheckFlashMailbox(COMMAND_BSL_CONFIG) !=BOOT_OVERRIDE_AND_MAILBOX_OPERATIONS_SUCCESS)
{
for(i = 0; i < 10000; i++);
// Do reeboot reset when S1 is pressed
if((P1->IN & BIT1)==0)
{
SysCtl_rebootDevice();
}

}

If i hold the Button P1.1 down on the MSP432 Launchpad Red, the CPU goes to "SysCtl_rebootDevice()"  once it started.

On the windows side i start the BSL scripter and it cannot communicate with MSP432:

        [ERROR_MESSAGE]Initialization of BSL P432 failed! Exit the scripter!

The BSL Scripter works when MSP432 is empty or no programm is flashed.

Now that i have one flashed i want to hardware invoke BSL on MSP432.

Any idea?