Using Classic Outlook on Windows for personal email, calendar, and contact management
Reset the Office cache, it should fix the problem:
- Close Outlook
- Rename or Remove these two folders: %LOCALAPPDATA%\Microsoft\Office\16.0\wef %userprofile%\AppData\Local\Microsoft\Outlook\HubAppFileCache
Re-open Outlook and click the "To-Do" shortcut, and it should open without issue.
This fixed a user we had. Thank you for this.
This fix was attempted and it did not work for me. On the latest version and build of Version 2307 (Build 16626.20170)