Error Transmit "cannot load from non-primitive location"

Hi,

i try to transmit data. The expression window shows "cannot load from non-primitive location "cannot load from non-primitive location" . What does it mean?

My code:

uint8 tx_data[8] = {0x11,0x22};
uint8 *tx_ptr = &tx_data[0];

void main(void)
{
    canInit(); //CAN intialisieren

    canTransmit(canREG1, canMESSAGE_BOX1, tx_ptr);

    while(1);
}

pic:

Best regards

Dennis