Aside from an entire layer of a print warping, you may have smaller arcs on highlighted regions, which in-turn commonly lead to more abstract mutation in the continual series of printing. The fix here is somewhat similar to your standard overheating procedure. Her's some suggestions to fix your problem,
- make sure that your fans are all turned on -just an simple "easy fix" recommendation
- decrease your temperature a bit. Maybe you are printing a little too hot in the first place. As long as your wider layers keep their integrity and your aren't low enough for the material to stuff up the extruder, taking a little off the edge may just do the job.
- try decreasing your printing speed; this will give those layers more time to set up. If you are not on a deadline, decreasing the speed is a simple fix for many problems.
- Try printing multiple objects at the same time -sure, focusing on one object at once can sometimes statistically reduce the percentage of error overall, but then again, by doing something that you know will eliminate an error in contrast to not doing so, you are already ahead of the game by trying it out. Many melted regions of prints occur at the narrow sections on the top of "trinket" pocket sized prints -with these sometimes you might as well want to print a few.