DoReleaseMouse(): can't release mouse - not captured

When modifying a pipeline to alter NamesAndTypes I get the following error.

Traceback (most recent call last):
File “/home/mplace/cellprofiler/CellProfiler/cellprofiler/gui/”, line 115, in on_corner_left_mouse_up
File “/home/mplace/anaconda/envs/cellprofiler/lib/python2.7/site-packages/wx-3.0-gtk2/wx/”, line 10649, in ReleaseMouse
return core.Window_ReleaseMouse(*args, **kwargs)
PyAssertionError: C++ assertion “g_captureWindow” failed at ./src/gtk/window.cpp(4505) in DoReleaseMouse(): can’t release mouse - not captured

Cell Profiler Version: 2016-05-03T18:31:00 ac0529e / 20160503183100
Ubuntu 14 LTS

It sounds like a wx error unfortunately; I’ve filed a bug report on our GitHub for our software engineers to take a look at, please follow up there for more information.