Error when accessing the setting icon in the builder

When I try to access the setting via the setting icon in the builder, it shows the below error msg. The experiment file is an old one and I’m trying to make a new version of it. I changed the exp. file name and deleted data, html, git folders and any hidden files before attemting to access the setting.

Traceback (most recent call last):
File “C:\Users\aexge3\AppData\Local\PsychoPy3\lib\site-packages\psychopy\app\builder\builder.py”, line 1139, in setExperimentSettings
timeout=timeout)
File “C:\Users\aexge3\AppData\Local\PsychoPy3\lib\site-packages\psychopy\app\builder\dialogs_init_.py”, line 1833, in init
timeout=timeout)
File “C:\Users\aexge3\AppData\Local\PsychoPy3\lib\site-packages\psychopy\app\builder\dialogs_init_.py”, line 515, in init
ctrls = self.addCategoryOfParams(theseParams, parent=page)
File “C:\Users\aexge3\AppData\Local\PsychoPy3\lib\site-packages\psychopy\app\builder\dialogs_init_.py”, line 629, in addCategoryOfParams
valType=self.params[fieldName].valType)
File “C:\Users\aexge3\AppData\Local\PsychoPy3\lib\site-packages\psychopy\app\builder\dialogs_init_.py”, line 756, in addParam
advanced=advanced, appPrefs=self.app.prefs)
File “C:\Users\aexge3\AppData\Local\PsychoPy3\lib\site-packages\psychopy\app\builder\dialogs_init_.py”, line 132, in init
parent, val, order=[‘Field’, ‘Default’])
File “C:\Users\aexge3\AppData\Local\PsychoPy3\lib\site-packages\psychopy\app\dialogs.py”, line 542, in init
raise AttributeError(msg)
AttributeError: The initial value for a ListWidget must be a list of dicts