TypeError: 'QVariant' object is not subscriptable

[marklit]

This error comes up during installation.

Couldn't load plugin 'flight_planner' due to an error when calling its classFactory() method 

TypeError: 'QVariant' object is not subscriptable 
Traceback (most recent call last):
  File "/Applications/QGIS.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 423, in _startPlugin
    plugins[packageName] = package.classFactory(iface)
  File "/Users/mark/Library/Application Support/QGIS/QGIS3/profiles/default/python/plugins/flight_planner/__init__.py", line 36, in classFactory
    return FlightPlanner(iface)
  File "/Users/mark/Library/Application Support/QGIS/QGIS3/profiles/default/python/plugins/flight_planner/flight_planner.py", line 51, in __init__
    locale = QSettings().value('locale/userLocale')[0:2]
TypeError: 'QVariant' object is not subscriptable

Python version: 3.9.5 (default, Sep 10 2021, 16:18:19) [Clang 12.0.5 (clang-1205.0.22.11)]
QGIS version: 3.34.3-Prizren Prizren, 47373234acd