Compling error: #28 expression must have a constant value

Hi 

After compiling I have an error: #28 expression must have a constant value. I do not know how to solve it. Can anyone help me ?

STATUS switch_stats_example( api_device_t *only_device )
{
UINT8 port1 = 1;

sc_read_ctrs_in_t read_in = {RIO_ALL_PORTS, NULL, &dev_ctrs }; // no error
sc_read_ctrs_in_t read_P1_in = {1, &port1, &dev_ctrs };  // error
sc_read_ctrs_out_t read_out;

};

typedef struct sc_read_ctrs_in_t_TAG
{
UINT8 num_ports; 
UINT8 *pnums;
sc_dev_ctrs_t *dev_ctrs; 
} sc_read_ctrs_in_t;

typedef unsigned char       UINT8;