Paradox of the magnetic field's collapse Imagine two strong electromagnets (X and Y) enough far from each other.
Facts:

1.) We know the magnetic fields spreading with the speed of light.
2.) When the magnetic fields reach the other electromagnets they will move.

What happens if you turn off X before its magnetic field reach Y? For example the magnetic field off X needs 1 second to reach Y and you turn of X after 0.9 second. 

1.) Both X and Y will not move. In this case the information about the collapse of the magnetic field is faster than the light. (0.1 s was
  enough to reach Y from X!)
2.) X will move but Y will not. In this case you can build a magnetic rocket engine wich doesn't need any propellant just energy.
3.) Y will move but X will not. The same than the previous.
4.) Both X and Y will move. How can X move if there is no magnetic field around it? In this case you can get information about Y on an
  extremely safety way. A third person cannot detect the informations
  from Y.

 A: 
3.) Y will move but X will not. The same than the previous.

This one is correct. However:

In this case you can build a magnetic rocket engine wich doesn't need any propellant just energy.

While this is true it would be much more efficient to simply shine a laser or a flashlight off the back of your rocket. 
A: 
What happens if you turn off X before its magnetic field reach Y? For example the magnetic field off X needs 1 second to reach Y and you turn of X after 0.9 second.

The magnetic field of an electromagnet is caused by a current of electrons flowing inside a coil. Powering off the current, the energy of the magnetic field gets converted back into kinetic energy of moving, against the previous direction, electrons in the coil Lenz’s Law. Furthermore magnetic field lines are always closed lines and nothing is able to cut them and to send them away from their source.
That means that a magnetic field does not fly away from its source. What radiates is electromagnetic radiation in the form of photons (from the accelerated electrons inside the coil). Them you get not back and they exert - because photons carrying a momentum - a light pressure on your second magnet.

1.) Both X and Y will not move. In this case the information about the collapse of the magnetic field is faster than the light. (0.1 s was enough to reach Y from X!)

The assumption is not correct. Not being influenced by the magnetic field from the first magnet the second has no information, will not move (except from the light pressure) and and the collapse of the magnetic field of the first coil is outside the event horizon of the second magnet. But answer 1 is correct, both magnets would not influence each other.
