This error could be caused because you are working offline, your proxy settings are preventing your connection, or you are experiencing intermittent network issues
First, please check if you have the latest updates for your Office Suite and Windows. If the updates did not solve the problem, please proceed with the following:
- Close all Office applications
- Rename the %localappdata%\Microsoft\DRM folder (e.g.:_DRM);
- Using the Internet Options as an Administrator (you can open the Internet explorer as an Admin and then use the Internet options there), please remove the expired certificates from the certificate store
- Open Outlook and try to open an encrypted email
- If the problem persists, try to create a new email (you can use RightsWATCH)
- Send the email
The DRM folder should contain:
- A CLC certificate
- A GIC certificate
- A Machine certificate
- Could have some EUL certificates
If this did not solve the problem, please contact Microsoft and ask for more support.