For what its worth I was getting CTDs every time I flew in the vicinity of KSEA too. It happened with every airplane I tried. Moving the autogen slider around did nothing for me but moving ADE_FTX_PNW_KSEA_elevation_adjustment.bgl seems to have fixed the problem for me so far. I was able to make a flight from Darrington to Vashon and back without a CTD for the first time in a long time. I'll try to make another flight tomorrow to see if it actually fixed the problem or if my flight today was just a fluke.