MSP430FR5847: Problem with switching MSP430FR5847 to 16 MHz clock

Hi,

I've got problem with switching MSP430FR5847 to 16 MHz clock. I'm running blink LED example plus I've got TB0 configured for PWM at channel 2 and pin P1.5

After executing this I have no signal at pin form TB0 and no blinking at P1.0:

    CSCTL0_H = 0xA5;						                                      //allow access to clock registers
    CSCTL3 &= ~(DIVS0 | DIVS1 | DIVS2 | DIVM0 | DIVM1 | DIVM2);           //clear MCLK and SMCLK dividers
    CSCTL1 &= ~(DCOFSEL0 | DCOFSEL1 | DCOFSEL2);             	      //set frequency to 16 MHz
    CSCTL1 |= DCOFSEL2;
    CSCTL1 |= DCORSEL;
    CSCTL0_H = 0x0;							                              //protect clock registers

when I change it into this code everything works fine but at 8 MHz clock...(signal at pin form TB0 and blinking at P1.0 are ok):

    CSCTL0_H = 0xA5;						                                      //allow access to clock registers
    CSCTL3 &= ~(DIVS0 | DIVS1 | DIVS2 | DIVM0 | DIVM1 | DIVM2);           //clear MCLK and SMCLK dividers
    CSCTL1 &= ~(DCOFSEL0 | DCOFSEL1 | DCOFSEL2);	                      //set frequency to 8 MHz
    CSCTL1 |= DCOFSEL1 | DCOFSEL0;
    CSCTL1 |= DCORSEL;   
    CSCTL0_H = 0x0;							                              //protect clock registers

Any ideas why?