You can sometimes temporarily reset the activation timer by running the Office Software Protection Platform script. This is not a permanent fix but may restore functionality briefly: Command Prompt as an administrator. Type the following command and press Enter: cd "\Program Files\Microsoft Office\Office16" (If using 32-bit Office on 64-bit Windows, use cd "\Program Files (x86)\Microsoft Office\Office16" Run the command: cscript ospp.vbs /act Alternatively, some users report running OSPPREARM.EXE
Restart and reinstall Office LTSC 2021 (production, not preview).
Before diving into the technical fixes, ensure you have the following: You can sometimes temporarily reset the activation timer
The Preview version has a different Product ID (PID) than the production LTSC. Your MAK key is like a key for a Toyota Camry – it won’t unlock a Honda Civic. You must uninstall the Preview and install the production version.
The only 100% reliable fix is to remove the expired Preview and install the production (non-expiring) version of Office LTSC 2021. Before diving into the technical fixes, ensure you
Resist the temptation to download "cracked" or "lifetime" preview versions. They will all expire eventually. Invest in a proper license or use the free web versions of Office. Your productivity is worth the cost.
This error is specific to the preview builds of Office 2021. Unlike retail or Microsoft 365 versions, preview builds have a hard-coded expiry date (usually 90–180 days after release). Once that date passes, the license enters a "grace period" and then locks down completely. The only 100% reliable fix is to remove
| If you are... | Do this... | | :--- | :--- | | | Uninstall the Preview. Install Office 2021 Home & Student (one-time purchase) or subscribe to Microsoft 365 Family. | | A business with a Volume License | Uninstall Preview. Download production LTSC from VLSC. Activate with your MAK or KMS key. | | A technician cleaning a client’s PC | Run SARA (Method 2B) + Registry cleanup (Method 3) before reinstalling. | | Someone who just wants Office to work right now | Use Office Online (free at office.com) temporarily while you reinstall the correct desktop version. |