Upgrade to Solex and it may display the cause, or search this forum or Youtube on how to connect to your Solo with Mission Planner and it will show you the cause. This error message often indicates a problem with an accelerometer (Part of IMU). If this is the problem, the fix is to replace your Pixhawk, but sometimes you can buy some time by giving your Solo a firm smack on its belly to temporarily free the stuck accelerometer.Hi, i have the same message error "Calibration error" i restarted several time my 3dr solo and nothing change that. Any solution?