Cannot open experiment settings window

OS (e.g. Win10): MacOS Mojave 10.14.6
PsychoPy version (e.g. 1.84.x): 2020.1.2
Standard Standalone? (y/n) If not then what?: y
What are you trying to achieve?: open experiment settings window

What did you try to make it work?:

What specifically went wrong when you tried that?:
592.8717 INFO Loaded monitor calibration from [‘2020_02_05 11:27’]
Traceback (most recent call last):
File “/Applications/”, line 2202, in setExperimentSettings
File “/Applications/”, line 1806, in init
File “/Applications/”, line 510, in init
ctrls = self.addCategoryOfParams(theseParams, parent=page)
File “/Applications/”, line 624, in addCategoryOfParams
File “/Applications/”, line 752, in addParam
File “/Applications/”, line 139, in init
parent, val, order=[‘Field’, ‘Default’])
File “/Applications/”, line 530, in init
raise AttributeError(msg)
AttributeError: The initial value for a ListWidget must be a list of dicts


I wanted to get rid of the experiment settings dialogue and I disabled it. Now I cannot open it anymore. Same problem as (Can't access experiment settings dialog).

I did read the Python to Javascript crib sheet and now I know I shouldn’t have disabled it, but now I don’t know how to be able to open the experiment settings again.

Any hint?


This is one we’ve fixed for the next bug fix release, but essentially you need to open the .psyexp file in a text editor (Notepad, Sublime Text, etc.) and replace the line:

<Param name="Experiment info" val="{}" valType="code" updates="None"/>


<Param name="Experiment info" val="{'participant': '', 'session': '001'}" valType="code" updates="None"/>

Thank you for your reply. I updated Psychopy and now I’m getting this error:

Traceback (most recent call last):
File “/Applications/”, line 1139, in setExperimentSettings
File “/Applications/”, line 1833, in init
File “/Applications/”, line 515, in init
File “/Applications/”, line 629, in addCategoryOfParams
File “/Applications/”, line 756, in addParam
File “/Applications/”, line 132, in init
File “/Applications/”, line 542, in init
AttributeError: The initial value for a ListWidget must be a list of dicts