Hey, All I just went to www.navdata.at the other day and downloaded the latest SID/STAR procedures and headed to KSEA. Well here is my problem whenever I enter KSEA in the Orgin or Dest fields in the RTE page I get this error "KSEA err: 16C rwy unkown." How can I fix this issue?Edit: I forgot to add im using the 609 AIRAC Demo cycle from navigraph.Ryan

The 0609 Airac is your problem. Runway numbers at SEA have changed since then (the next cycle I recall)... you could update airac or revert to an older sidstar file, or you could edit the runway numbers in the sidstar file by changing all instances of 16C to 16R and all instances of 34C to 34L. Lots of choices.

Thanks for the reply Dan. I managed to fix the problem by simply editing the wpNavAPT file and changing rwy 16R to 16C and 34L to 34C. All is good :-)- Ryan