I have been using a test print which is a simple rectangle 2mm thick. When printing task is about 90% the task ends suddenly without any warning or error. The USB/Serial connection with the computer is still alive.
It happens one of each three times a print the same part. It does not stops always at the same place, but it is always beyond 80%.
The head does not return to the home position, it stays siting on the last printed point, no motion on any of the axis. Using the control panel on the simplify3D I am able to move the Z axis up and go to home position. The preview window is also frozen.
Any hint will be welcome.