Office 2021 Proofing Tools Offline Installer

Go to File → Options → Proofing . Ensure the following are checked:

The ODT relies on a configuration file to know exactly what to download or install. You need to create an XML file tailored for Office 2021 proofing tools. Open Notepad or any text editor. Paste the following configuration code: office 2021 proofing tools offline installer

Look at the section.