module 'django.db.models' has no attribute 'SubfieldBase'

Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "C:\Users\91941\anaconda3\lib\site-packages\django\core\management\__init__.py", line 419, in execute_from_command_line
    utility.execute()
  File "C:\Users\91941\anaconda3\lib\site-packages\django\core\management\__init__.py", line 395, in execute
    django.setup()
  File "C:\Users\91941\anaconda3\lib\site-packages\django\__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "C:\Users\91941\anaconda3\lib\site-packages\django\apps\registry.py", line 114, in populate
    app_config.import_models()
  File "C:\Users\91941\anaconda3\lib\site-packages\django\apps\config.py", line 301, in import_models
    self.models_module = import_module(models_module_name)
  File "C:\Users\91941\anaconda3\lib\importlib\__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "C:\Users\91941\ProjectSafalHonge\safalhonge\CPanelAuth\models.py", line 5, in <module>
    import mathfield
  File "C:\Users\91941\anaconda3\lib\site-packages\mathfield\__init__.py", line 2, in <module>
    from mathfield.models import *
  File "C:\Users\91941\anaconda3\lib\site-packages\mathfield\models.py", line 15, in <module>
    class MathField(models.TextField):
  File "C:\Users\91941\anaconda3\lib\site-packages\mathfield\models.py", line 19, in MathField
    __metaclass__ = models.SubfieldBase
AttributeError: module 'django.db.models' has no attribute 'SubfieldBase'

how do I resolve this error??

SubfieldBase was deprecated in Django 1.8 (April 2015), and removed in Django 1.10. Here’s the release note: Django 1.8 release notes | Django documentation | Django

It looks like this mathfield package you’re using is severely out of date, since it hasn’t been updated for that change 6 years ago. I would find an alternative package.