Hello everyone, I know I'm a little late but here is the solution that worked for me. I have a Galaxy S9+ with the same problem as the person who posted that the file is found in "data >> user >> 0 >> (series of numbers)."
The file is nowhere to be found in my phone's files, so I couldn't delete it using the Files app.
Also, Samsung made it so you can't uninstall Excel (the app that messed up in my case) or any Microsoft app.
Here is what you need to do:
1. In your apps menu, touch and hold on the app giving you the error.
2. From the menu that appears, choose "App Info."
3. Tap "Storage."
4. Tap "Clear Data."
5. Tap '"Ok."
Due to Samsung's weird choice, this is the closest we can get to uninstalling and reinstalling the app, but it works.