I've flown this route several times with the PMDG 737 slippery 800 and less slippery 900 and have had the same problem of "descent path unachievable" message. The route is KSAN-KSFO FL320 PDRZ1 IKAYE RIZIN SPLNT SERFR2 RWY 28R. I've had this problem more often than not with other flight plans with the PMDG. The flight is good until about 10,000 in the STAR and I get the message we're too high. Fuel and payload is within range. By the time I get the message there's no way to descend manually that won't make a passenger puke. This is a reasonable flight plan with an established STAR. I understand the 737 FMC is delicate, can I expect this with most flights?
Thanks in advance for your help!