Addon cannot be enabled

[emshupisim]

error message:

Traceback (most recent call last):
  File "C:\Program Files\Blender Foundation\Blender 2.93\2.93\scripts\modules\addon_utils.py", line 351, in enable
    mod = __import__(module_name)
  File "C:\Users\esuta\AppData\Roaming\Blender Foundation\Blender\2.93\scripts\addons\shape_keys_plus-master\__init__.py", line 4, in <module>
    from shape_keys_plus import core
ModuleNotFoundError: No module named 'shape_keys_plus'

[MichaelGlenMontague]

You downloded the GitHub repository directly (the "master" branch which gets downloaded as shape_keys_plus-master) without renaming the folder inside of the .zip file back to shape_keys_plus, which is the missing module. The newest version is available on the Releases page so that this extra step isn't necessary.