Maybe someone can help me . I have not been able to fly this plane since the first time I purchased it correctly because of a problem with the autopilot. Sometimes (it does not follow a pattern) the airplane starts banking  until it crashes in the ground. I does not matter what I do I can select HDG SEL, LNAV, LOC it will continue to bank. The only way I can make the bank stop is to disconnect the autopilot and restart Flight Simulator. There are many other things like sometimes the FMC crashes because of the Navigation Data. But those things you can work around but this messes up your whole flight and you never know when it is going to happen. If anybody can help please do. Thank You