Error states: 

"Sorry, we couldn't open https://[sharepoint]/[filename]"

Behavior:

You are attempting to open a file locally cached on your computer from OneDrive or Sharepoint.

You are attempting to open a file from Sharepoint (web) in the desktop version of an app

Solution:

1. Close all Office programs (including Outlook, Word, Excel, etc).

2. Copy and paste the following into the Windows start menu or file explorer address bar: %localappdata%\Microsoft\Office\16.0\ and press ENTER

(Start menu)

(File explorer)

3. Find the OfficeFileCache folder

4. Select the folder and delete it.