Sorry, we couldn’t open Offline file error
You might encounter this error if you have Windows 10 installed and special folders (for example, Documents or Favorites) are redirected to a file share, where the user data in the redirected folders are cached locally through the Offline Files feature. Also, Windows Information Protection (also known as Enterprise Data Protection) is enabled on the system and you’re using an application (in this case, Word) that are managed by Windows Information Protection – If you try to open a file while working offline in this scenario, the attempt fails. This issue occurs because the Offline Files feature does not support Windows Information Protection.
If you cannot open a file while working offline, Microsoft recommends you use one of the following methods: According to Microsoft, there are no plans to update Offline Files to support Windows Information Protection. It’s recommended that you migrate to a modern file sync solution such as Work Folders or OneDrive for Business. And that’s it, folks!