Something (not) Funny Occured

I started printing with Zortrax M200 with %20 fan speed, .14 resolution and normal speed... A few hours later I went to check the machine and saw this... After that I stopped the print process... 

It is the first time I saw such a thing on a 3D printer and it was really weird... What you guys think about the reason? It is really curious...

Do the XYZ axis maintenance inspection -

Probably just grub screws on pulleys are loosen.

I had the same problem and did the XYZ axis maintenance as Sam recommended via support and it cured my problem. Hasn't happened since!

I had an idea about it... There was a separation occured between the raft and the part and maybe extruder stucked and because of it it could not move. I checked the studs and done the maintenance and did not again faced with the problem. Thanks a lot!