I am using Anaconda with Python 3.5.2, Matplotlib 2.0.2, PyQt5.6 on a windows 10 machine. When I import matplotlib.pyplot as plt I get the following error:
I just had the same error (even though on Windows 7). For me the problem was that there was an old matplotlibrc file in C:\Users\\.matplotlib\matplotlibrc which overwrote the settings from my environment's matplotlibrc file. Deleting that file solved the issue for me.