Hello, Just a bit more information about this problem. I have a feeling I may be making a fundamental error with activating the autopilot since I'm not familar with Airbus systems. I'd been running the PMDG 777 and the the flightplan operated flawlessly. All I had to do was click the Autopilot and it followed the flightplan, automatically ascending, controlling airspeed etc. Before I raised this problem with the autopilot I'd uninstalled the Airbus A350 via IniManager, checked that all a350 folders had been deleted, deleted liveries and also the WASM folder. I purchased this aircraft in March so reinstalled it with the April update. In regards to activating the autopilot, I dial in altitute i.e. FL330, speed 250 knots. Do I have to click the altitude knob? Also the only way I can activate the AP1 is to hold the Z key. It will not activate when I click it with the mouse. Auto Throttle will activate with the mouse. Regards Rod