Problems with ColorFabb XT: over extrusion
Level the bed and check your filament diameter.
Usually this occurs because the space between the nozzle and bed is greater than it should be for the material put out of the nozzle.
Such conditions can happen for a variety of reasons but usually it's an improper bed leveling.
Filament diameter vs what your slicer program thinks is the filament diameter is one of the easier ways to control material output after bed is level.  (Sometimes I tell my slicer that the material is smaller than it really is to get it to output more)
Sometimes your z axis moves too much or you are using a layer height that your z axis could not handle.  You may have to increase layer thickness.
Getting the temperatures into a point where it is not too hot and not too cold is also important.  If the material is too cold, it won't stick.  If too hot, it cools and shrinks by the time your new layer gets to it ( making it lower or warped out of place from where the new layer tries to stick )  Increasing bed temperatures is a good way to help counteract the shrinkage.