This error happens when the toolhead detached from the rods, there are two reasons - (1) the toolhead bumped into the printing object, or (2) some force made it - to drastically reduced the latter reason, kindly check the following list:
1. The connector of the toolhead is facing the front side of the machine.
2. The cable should not be twisted and should be smoothly arranged then plugged.
3. The ball joints are lubricated.
Please check this tutorial as well:
How to Pass the Movement Test