Hi @ChairmanAlex, welcome to the forum 
That message indicates that when it tried to spin thruster 1, the vehicle didn’t move the way that it expected it to. The auto-direction detection functionality assumes all the thrusters have been connected to the correct places in the Pixhawk, and that the vehicle is in the water, and it tries to determine if any of the thrusters are configured backwards in the firmware. That’s necessary because the thruster windings aren’t consistent, so it’s not known which way they’ll spin by default.
That’s unexpected. It may be worth resetting to the default parameters from the Parameters page.
Also, are you using our Basic ESCs for controlling your thrusters? Other ESCs are often not bidirectional by default, in which case the 1500us “stopped” signal that ArduSub sends by default for all the thrusters may be interpreted as a mid-range throttle signal by ESCs that are configured as single-directional. If that’s the case you’ll either need to get different ESCs, or reconfigure/flash new firmware onto your existing ones to make them bi-directional. This comment may be worth a read