Window layout setting error

[Fukuhara-Kichinosuke]

Description

What steps will reproduce the problem?

1. display tab
2. close current pane
3. repeat step2.

What is the expected output? What do you see instead?

• show default window layout

Please provide any additional information below

File "C:\Users\xxx\AppData\Local\Continuum\Anaconda3\lib\site-packages\spyder\app\mainwindow.py", line 2248, in maximize_dockwidget
self.last_plugin.dockwidget.toggleViewAction().setDisabled(True)
AttributeError: 'NoneType' object has no attribute 'dockwidget'

Version and main components

• Spyder Version: 3.2.3
• Python Version: 3.6.1
• Qt Versions: 5.6.2, PyQt5 5.6 on Windows

Dependencies

pyflakes >=0.6.0 :  1.5.0 (OK)
pycodestyle >=2.3:  2.3.1 (OK)
pygments >=2.0   :  2.2.0 (OK)
pandas >=0.13.1  :  0.20.1 (OK)
numpy >=1.7      :  1.12.1 (OK)
sphinx >=0.6.6   :  1.5.6 (OK)
rope >=0.9.4     :  0.9.4-1 (OK)
jedi >=0.9.0     :  0.10.2 (OK)
nbconvert >=4.0  :  5.1.1 (OK)
sympy >=0.7.3    :  1.0 (OK)
cython >=0.21    :  0.25.2 (OK)
qtconsole >=4.2.0:  4.3.0 (OK)
IPython >=4.0    :  5.3.0 (OK)
pylint >=0.25    :  1.6.4 (OK)