Activation Problems

Fix Microsoft 365 Deactivating Office Apps After Date and Time Change

Khadija Khan Oct 19, 2026 869 views

Question details

The user is experiencing Microsoft 365 authentication failures and read-only restrictions after altering the system date and time.

Fix Microsoft 365 Deactivating Office Apps After Date and Time Change

Product: Microsoft 365
Device & OS: Windows 11
Scenario: Changing the system clock to a past or future date causes Office to fail subscription validation checks with Microsoft servers.
Observed behavior: Microsoft 365 apps prompt for sign-in, display authentication errors, and switch to a read-only mode that prevents document editing.

Before you start

Ensure your computer has an active internet connection, as restoring authentication requires contacting Microsoft's licensing servers to verify your subscription status.

Solution 1Recommended

Restore Correct Windows Date, Time, and Time Zone

Synchronizing your system clock automatically with the internet is the primary fix for resolving subscription validation errors.

Microsoft 365 relies heavily on accurate timestamps to validate security certificates and subscription tokens. A significant mismatch between your system clock and Microsoft's servers will block the authentication process.

Access Date and Time Settings

Right-click the clock located on the right side of the Windows taskbar and select "Adjust date and time" from the context menu.

Enable Automatic Synchronization

Toggle the switches for "Set time automatically" and "Set time zone automatically" to the "On" position.

Sync with Time Server

Click the "Sync now" button under the Additional settings section to ensure your clock perfectly matches the global internet time servers.

Restart Office Apps

Close any open Microsoft 365 applications, relaunch them, and sign in with the Microsoft account associated with your active subscription.

Restore Correct Windows Date, Time, and Time Zone

Quick Check: If you are traveling, ensure your computer's time zone settings match your current physical location to avoid regional authentication discrepancies.

Solution 2

Clear Outdated Microsoft Office Credentials

If fixing the date and time does not restore access, clearing corrupted cached credentials forces Office to generate a fresh sign-in token.

Solution 3

Repair or Reinstall Microsoft 365

When authentication components become permanently damaged due to system changes, a full repair or reinstallation of the software is required.

Free Microsoft Office alternative

Try WPS Office for a Hassle-Free Offline Experience

If Microsoft 365 subscription validation errors are locking you out of your work, switch to WPS Office. It provides powerful productivity tools without the strict, constant background authentication checks, allowing you to edit documents smoothly anytime.

1. Download the Installer: Visit the official WPS website and download the free installation package.
2. Install the Suite: Run the installer and follow the quick on-screen instructions to set up the lightweight software.
3. Open Your Office Files: Directly open your existing Word, Excel, or PowerPoint files in WPS Office and resume your work without activation prompts.

Fully compatible with Microsoft Office formats including .docx, .xlsx, and .pptxWorks seamlessly offline without strict background subscription checksLightweight installation with a highly familiar user interfaceFree to use for everyday document, spreadsheet, and presentation tasks

microsoft office alternative - wps office

Frequently Asked Questions

Why does changing the date and time affect Microsoft 365 activation?

Microsoft 365 establishes secure connections with its licensing servers using security certificates. These certificates rely on precise timestamps. If your system clock is incorrect, the certificates appear invalid or expired, which blocks the authentication process.

Can I use Microsoft 365 offline without internet time syncing?

Yes, Microsoft 365 can be used offline for up to 30 days before requiring a connection to verify the subscription. However, manually backdating or drastically changing the system clock triggers an immediate security check that requires online validation.

What does 'Unlicensed Product' or 'Read-Only' mean in Office apps?

This warning indicates that Microsoft 365 could not verify your active subscription status. Consequently, the apps lock down editing features, allowing you to only view and print your documents until the activation issue is resolved.

Will clearing Office credentials delete my saved documents?

No. Removing saved entries in the Windows Credential Manager only deletes cached passwords and sign-in tokens. Your personal files, documents, and system settings remain completely safe and untouched.

Installation & Activation