“Trouble Reading Memory Block at …

Hallo Everyone, i have again another problem:
i am using TI MSP430f5438 with code composer: i create receiving-task and a sender ISR is already given in Hardware Abstraction Layer “HAL”.
after the first sending and receiving, the second sending is not working well. here is the sending ISR:
#pragma vector=USCI_A1_VECTOR
__interrupt void USCI_A1_ISR (void)
char cChar= NULL;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
cChar = UCA1RXBUF;
xQueueSendFromISR( xPROTQueue, &cChar, &xHigherPriorityTaskWoken );
} with the debuging and making Step into i found that the code stops at this ISR in port.c :
#pragma vector=configTICK_VECTOR
interrupt void vTickISREntry( void )
extern void vPortTickISR( void ); #if configUSE_PREEMPTION == 1
extern void vPortPreemptiveTickISR( void );
extern void vPortCooperativeTickISR( void );
} and then i get this error: MSP430: Trouble Reading Memory Block at 0xca5a4 on Page 0 of Length 0xc9: Invalid parameter(s) can anyone say what the problem here can be. Best Regards,