AttributeError: 'AboutScreen' object has no attribute 'about_label'

[lk1983823]

When run the main.py file, it shows errors:

 Traceback (most recent call last):
   File "main.py", line 500, in <module>
     QuEStApp().run()
   File "/home/lk/.pyenv/versions/anaconda3-2020.02/envs/rlai/lib/python3.7/site-packages/kivy/app.py", line 954, in run
     self._run_prepare()
   File "/home/lk/.pyenv/versions/anaconda3-2020.02/envs/rlai/lib/python3.7/site-packages/kivy/app.py", line 924, in _run_prepare
     root = self.build()
   File "main.py", line 446, in build
     sm = QuEStScreenManager(transition=RiseInTransition(duration=0.2, clearcolor=[1, 1, 1, 1]))
   File "main.py", line 221, in __init__
     self.about_screen = AboutScreen()
   File "main.py", line 198, in __init__
     third_party_code_licenses])
 AttributeError: 'AboutScreen' object has no attribute 'about_label'

I am using:
Ubuntu 16.04
Python 3.7.8
Anaconda 3-2020.2
QuESt version 1.2.g

[cancom84]

could you tell me how you installed QuESt?

[lk1983823]

could you tell me how you installed QuESt?

python setup.py install