Here is my problem: after several good prints, i have this problem suddenly.

To start: the bed is leveled perfect, i use Cura (standard) and use the right standard settings for PLA (200 degrees C and 60 degrees C). I have restored all adjustments in the interface to factory default. I start printing and it runs perfect. Then when the printer is about 25% done, the printer head levels up and hangs about 1 centimeter above the print and just spits out the PLA in a mess (see attachment). Who has an idea how to solve? Thanks in advance.