Sky_Trotter

Hi all Yesterday I wanted to depart from EFHK I set the FMC carefully and I turned off the "Realistic autopilot engagement" from the FMC, after departure when I wanted to engage the autopilot, I faced with VNAV SPD error and suddenly the autopilot had disconnected automatically. After that I tried alot to solve this problem but I couldn't understood why it happened ... So if you have any recommendations let me know please to solve it ;-)