Reprap Prusa I3 problem with "waiting for user input"

Hi everyone, I have a problem with my 3d printer. At about layer number 40, suddenly the nozzle stops printing then moves in the z axis a couple of steps and then goes to the maximun distance in the x axis, and displays the message "waiting for user input".
It wasn't like this before, I printed so many prints before this stated to happen, don't know what is causing it, and ruined many of my prints because after I press to resume the print, the nozzle missaligns with the already printed part.

Reprap Prusa I3. http://www.ebay.com/itm/Newest-DIY-3...item2a5bc2e135
Cura v 15.04.3.

With prints lower than 40 layers I don't experience that issue. Tried with my own models done in blender, and also with models downloaded from thingivers.com and have the same issue

Any thoughts?

Solved, I updated cura version, and prints larger than 40 layers print without that issue