Before fixing the problem, it helps to understand it. Microsoft distributes "Preview" versions of Office to businesses and testers before the final release. These previews include:
These builds are designed to expire 30 to 180 days after installation. Once expired, Microsoft disables all editing features to push you toward a licensed, permanent version.
Q: Will I lose my Word/Excel documents?
A: No. Your documents are saved separately on your hard drive or OneDrive. Uninstalling Office does not delete your .docx or .xlsx files.
Q: Can I just set my system clock back? A: No. Office 2021 previews use cryptographic time-stamping. Changing the date will break SSL certificates (websites will show errors) and still won’t unlock Office.
Q: Is there a free alternative? A: Yes. If you cannot buy Office, consider installing LibreOffice (free, open-source) or using the Microsoft 365 Web Apps (Word/Excel for free in your browser).
A: Your KMS host might be serving a preview KMS key. Contact your admin to switch to the LTSC 2021 Volume License KMS key. Before fixing the problem, it helps to understand it
If you're still experiencing issues, use the Microsoft Office Uninstall Support Tool:
Conclusion
The "Microsoft Office LTSC Professional Plus 2021 preview has expired" error can be frustrating, but it's resolvable. By trying the solutions outlined in this article, you should be able to fix the issue and continue using Office LTSC Professional Plus 2021 without any problems. If you're still experiencing issues, consider contacting Microsoft support for further assistance.
This may re‑enable Office for a short grace period but does not convert preview to full version. Suitable only for data recovery before uninstalling.
Steps:
Q: I don't have a license key yet. Can I keep using the Preview? 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.
Q: The uninstall failed. How do I force remove it? A: Use the Microsoft Support and Recovery Assistant (SaRA).
Q: Will I lose my documents? A: Uninstalling Office does not delete your Word, Excel, or PowerPoint documents. They remain on your computer. However, it is always good practice to back up important files before performing software maintenance.
Report Title: Resolution Protocol for Microsoft Office LTSC Professional Plus 2021 Preview Expiration Error
Date: April 12, 2026 Affected Software: Microsoft Office LTSC Professional Plus 2021 (Preview Build) Error Message: “Your Office Preview has expired” / “Microsoft Office LTSC Professional Plus 2021 Preview has expired” These builds are designed to expire 30 to
If you have a legitimate license key for the final version of Office LTSC 2021, you should uninstall the preview and install the official version.
Step 1: Uninstall the Preview
Step 2: Download the Official Version
Step 3: Install and Activate