You might see this error when entering phase_shift values for output clocks in the Altera PLL megafunction in the Quartus® II software version 13.0:
Error: PLL Output Counter parameter 'phase_shift' is set to an illegal value of '<phase_shift value> ps' on node '<node name>'.
There is a bug in the Quartus II software version 13.0 that can occur when you specify your PLL output counter phase_shift value in degrees in the Altera PLL megafunction.
Open the Altera PLL megafunction and change your phase_shift value from degrees to ps.
This problem is scheduled to be fixed in a future version of the Quartus II software.