This error indicates a problem with the cached wrapper classes used by the pywin32 (win32com) package and may cause problems when trying to call the Excel COM API via the win32com package.
This is a problem with the pywin32/win32com package and seems to sometimes happen after changing or upgrading the version of the pywin32 package, or it could also be caused by different Python sessions overwritting each others files. Once the files are deleted then they are recreated the next time they're needed, fixing the problem.
PyXLL has some settings to help with this problem.
Please see https://www.pyxll.com/docs/userguide/config/pyxll.html#win32com-settings for details.
We suggest setting "win32com_gen_path" to somewhere other than win32com's default folder initially.That setting can be a relative path to the pyxll.cfg file, ensuring that it's only used by PyXLL.
If you still get these errors happening after setting "win32com_gen_path" you can also use the "win32com_delete_gen_path" setting to delete the cache folder each time Excel starts, causing the wrapper classes to be regenerated each time.
[PYXLL]
win32com_gen_path = ./gen_py
win32com_delete_gen_path = 1