Generally this is a result of the firewall/internet settings blocking the add-in. Please ask your system administrator for help. Here are some steps to make sure everything works properly:

  1. Make sure you have an active internet connection.
  2. If you're using a controlled device, make sure external websites such as are not blocked.
  3. If the problem persists, please try to install another add-in: Adobe Sign. If the Adobe add-in works, but the LanguageTool add-in doesn't, we know the issue is specific to LanguageTool.