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Script previously working correctly not running anymore (caused by Windows update 1903)

Hello everybody,

I am new to psychopy, I have been using it this year to develop a cognitive task which has with ups and down relative worked well in the past few months. I am still recruiting participants and in the last weeks the task stopped working.
on the computer of my desk (which has to screen) I found the problem doesn’t persist if I unplugged one of the 2 screens (not really an option though). Moreover I actually don’t use my computer but a laptop and it has been working extremely inconsistently (the same script without modifying anything): it worked 2 days, then other 2 days stops working and so on.

Today, trying the task again and receive these messages:

Traceback (most recent call last):
  File "O:\bandit_task\bandit_task\", line 612, in <module>
    window, rectangle_right, rectangle_left, toy_bear, toy_duck, happy_face, neutral_face, sad_face, fixation_cross, right_highlight, left_highlight, rectangle_time, rectangle_time_passing = init_elements_in_window()
  File "O:\bandit_task\bandit_task\", line 98, in init_elements_in_window
    window = init_window()
  File "O:\bandit_task\bandit_task\", line 148, in init_window
    color=[0, 0, 0])
  File "C:\Program Files (x86)\PsychoPy3\lib\site-packages\psychopy\visual\", line 389, in __init__
    self.backend = backends.getBackend(win=self, *args, **kwargs)
  File "C:\Program Files (x86)\PsychoPy3\lib\site-packages\psychopy\visual\backends\", line 32, in getBackend
    return Backend(win, *args, **kwargs)
  File "C:\Program Files (x86)\PsychoPy3\lib\site-packages\psychopy\visual\backends\", line 227, in __init__
    self._origGammaRamp = self.getGammaRamp()
  File "C:\Program Files (x86)\PsychoPy3\lib\site-packages\psychopy\visual\backends\", line 329, in getGammaRamp
    return getGammaRamp(self.screenID, self.xDisplay)
  File "C:\Program Files (x86)\PsychoPy3\lib\site-packages\psychopy\visual\backends\", line 128, in getGammaRamp
    raise AssertionError('GetDeviceGammaRamp failed')
AssertionError: GetDeviceGammaRamp failed
Exception ignored in: <bound method Window.__del__ of <psychopy.visual.window.Window object at 0x000001C3B9A781D0>>
Traceback (most recent call last):
  File "C:\Program Files (x86)\PsychoPy3\lib\site-packages\psychopy\visual\", line 501, in __del__
  File "C:\Program Files (x86)\PsychoPy3\lib\site-packages\psychopy\visual\", line 1327, in close
    self.backend.close()  # moved here, dereferencing the window prevents
AttributeError: 'NoneType' object has no attribute 'close'

Do you have any idea to explain this inconsistency and this window problem?

Many thanks,



This is caused by a broken update to Windows itself. Hopefully Microsoft will fix it soon. We’re working on a workaround so that people aren’t affected if they don’t actually need to set gamma themselves (that fix will be in PsychoPy 3.2.0, in a few weeks) but ultimately the issue is the windows update.

See Error message since windows update to 1903

Thank you so much for your quick response,
Looking forward the solution or the new version of psychopy!

Dear Jon,

is the new version of psychopy over-running the problem of the windows update previously mentioned?
In the “fixed” points of the version I haven’t seen this.