#!/usr/bin/env python

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
print matplotlib.__version__ # 2.2.0rc1

fig = plt.figure()
axes = fig.add_subplot(111)

d1 = [29388871, 12448, 40, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
d2 = [28396236, 981940, 22171, 537, 123, 88, 41, 42, 40, 26, 26, 84, 6, 2, 0, 0, 0, 0, 0]
axes.plot(d1, label='series 1')
axes.plot(d2, label='series 2')
axes.legend(ncol=5, mode='expand')

#### THIS IS WHERE THE CRASH HAPPENS
plt.tight_layout(rect=[0,0.08,1,0.92])

fig.savefig('test.png', format='png', bbox_inches='tight')
plt.close(fig)

Traceback (most recent call last):
  File "minimal_example.py", line 20, in <module>
    plt.tight_layout(rect=[0,0.08,1,0.92])
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/pyplot.py", line 1366, in tight_layout
    fig.tight_layout(pad=pad, h_pad=h_pad, w_pad=w_pad, rect=rect)
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/figure.py", line 2275, in tight_layout
    pad=pad, h_pad=h_pad, w_pad=w_pad, rect=rect)
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/tight_layout.py", line 328, in get_tight_layout_figure
    pad=pad, h_pad=h_pad, w_pad=w_pad)
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/tight_layout.py", line 115, in auto_adjust_subplotpars
    if ax.get_visible()])
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/axes/_base.py", line 4182, in get_tightbbox
    bb.append(child._legend_box.get_window_extent(renderer))
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/offsetbox.py", line 266, in get_window_extent
    w, h, xd, yd, offsets = self.get_extent_offsets(renderer)
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/offsetbox.py", line 388, in get_extent_offsets
    for c in self.get_visible_children()]
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/offsetbox.py", line 259, in get_extent
    w, h, xd, yd, offsets = self.get_extent_offsets(renderer)
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/offsetbox.py", line 478, in get_extent_offsets
    sep, self.mode)
  File "/Users/ewels/miniconda2/envs/work/lib/python2.7/site-packages/matplotlib/offsetbox.py", line 81, in _get_packed_offsets
    sep = (total - sum(w_list)) / (len(w_list) - 1.)
TypeError: unsupported operand type(s) for -: 'NoneType' and 'float'

axes.legend(loc='lower center', bbox_to_anchor=(0, -0.22, 1, .102), ncol=5, mode='expand', fontsize=8, frameon=False)