Loading at 80% doesn't have anything to do with our airport, since we *start* loading AFTER the progress bar ends.
A loading problem at that stage it's either a problem with an AI airplane, or a problem with a file of the surrounding scenery (vector, mesh, landclass), and you are problem mislead it's has something to do with KMEM, but only because the problematic file is something in the KMEM area, or the problematic AI is one that, because of schedule and location, happens to be generated only there.