If you are running the preview on a Mac and having activation issues, Microsoft recommends using the license removal tool. Download and run the Office for Mac License Removal Tool .

It will cause certificate errors on the web and break file timestamps.

To properly fix the issue, one must first understand why it is occurring. The "Preview" or "Beta" versions of Microsoft Office are time-limited releases designed for testing and compatibility checks. Unlike the final Retail or Volume License versions, these previews contain hard-coded expiration dates.

Restart Word or Excel, and log in with your valid license to reactivate. 3. Important Considerations

A: No. Once the preview expires, the applications enter "Reduced Functionality Mode" or become completely unusable. You cannot retrieve documents or create new ones. You must purchase a license and install the official software.

If you do not have a license key and need a working version of Office, you must uninstall the preview version first.

The only definitive fix is to remove the expired preview and replace it with a build of Office LTSC 2021. However, standard uninstallation via the Windows Control Panel often leaves behind activation tokens and registry keys that confuse the new installation. To perform a clean sweep:

If your environment uses KMS activation for volume licensing and the preview version is stuck on a different activation method, you can manually convert it to KMS:

Microsoft Office LTSC (Long-Term Servicing Channel) Professional Plus 2021 is a version of Microsoft Office that is designed for organizations that require a stable and predictable platform. However, users of the preview version of Office LTSC Professional Plus 2021 may encounter an issue where the software displays a "preview has expired" message. This paper provides a step-by-step guide on how to fix this issue.