python-win32com excel com model started generating errors

Execute this command line in a powershell or cmd (NOT in Administrator mode => wouldn't work for me)

   python -m win32com.client.makepy "Excel.Application"

It fixes all errors and you don't have to change your python code. And keep using

win32com.client.gencache.EnsureDispatch("Excel.Application")

With gencache.EnsureDispatch you have access to the constants of the application loaded dynamically by makepy which must have the registered application (in our case Excel.Application). If you have the same problem with Outlook, use "Outlook.Application" in above.

If still not working, reinstall pywin32 of your python distribution

<path to python root or venv>\pip.exe uninstall pywin32
<path to python root or venv>\pip.exe install pywin32

A more straightforward solution was posted in a related question Issue in using win32com to access Excel file.

Basically, you just need to delete the folder C:\Users\<your username>\AppData\Local\Temp\gen_py and rerun your code.

What has worked for me is:

excel = win32.gencache.EnsureDispatch('Excel.Application')
#change to =>
excel = win32.Dispatch('Excel.Application')

I had the same issue and I resolved it by following the instructions here: https://mail.python.org/pipermail/python-win32/2007-August/006147.html

Deleting the gen_py output directory and re-running makepy SUCCEEDS and subsequently the test application runs OK again.

So the symptom is resolved, but any clues as to how this could have happened. This is a VERY long running application (think 24x7 for years) and I'm concerned that whatever caused this might occur again.

To find the output directory, run this in your python console / python session:

import win32com
print(win32com.__gen_path__)

Based on the exception message in your post, the directory you need to remove will be titled '00020813-0000-0000-C000-000000000046x0x1x9'. So delete this directory and re-run the code. And if you're nervous about deleting it (like I was) just cut the directory and paste it somewhere else.

I have no idea why this happens nor do I know how to prevent it from happening again, but the directions in the link I provided seemed to work for me.