What slicer you use? can you please share your settings? I recently got Ultimaker 2+ and I use simplify3d yet I am still not had a successful print with simplify 3d under 150 micron.
I use colorfabb PLA
I been mostly failing getting the first layer to print good, what is been doing is making like gaps in the first layer then I had issue not filling between the lines, I increased the layer width and kept the layer height same, but only failing anything under 100 micron at 100 micron the printer works great, I still have to get use to it I guess I know its not the printer fault but just getting used to simplify3d with ultimaker together I used it for flashforge and Airwolf, and I have cube pro (which I hate so much)