Understanding these root causes will help you map out a clearer resolution path. In many cases, performing simple checks—like verifying correct usernames and valid licensing—will resolve the issue quickly. After you run any troubleshooter, Get Help provides details on any findings and suggestions for possible remedies. If one of these resolves your problem, close the app and continue working. Use the Microsoft 365 shared computer activation (SCA) troubleshooter to enable shared computer activation for Microsoft 365 applications.

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Sometimes cached credentials on your device or Troubleshoot Office 365 Sync and Login Issues a corrupted Office profile can lead to repeated sign-in prompts or activation failures. Office 365 uses several internet endpoints and cloud services to authenticate users and validate licenses. If these connections are disrupted, sign-in and activation will fail. Use the Excel check troubleshooter to resolve Excel for Windows startup, hang, or crash issues.

1 Troubleshooting Sign-In Errors on Shared Devices

For codes linked to storage limitations, free up disk space or install on an external drive. The Microsoft Support and Recovery Assistant can automate fixes for common error codes. The "Unlicensed Product" error usually indicates an inactive or unlinked subscription.

What should I do if email syncing fails in Outlook?

Get Help has troubleshooters for Microsoft 365 you can run for many common scenarios. These often help resolve issues without the need to contact support. If a troubleshooter is available for your issue, select Start to run that troubleshooter.

Fix #5. Update the Browser or Microsoft 365 App

• In this comprehensive guide—KB113—we’ll explore the most common causes of Office 365 sign-in and activation issues.
• Check your internet connection, as weak connectivity can cause issues.
• The "Unlicensed Product" error usually indicates an inactive or unlinked subscription.
• Regularly cleaning up your hard drive or upgrading hardware like RAM can also enhance performance.
• If one of these resolves your problem, close the app and continue working.
• For work or school accounts, confirm with your organization that your account is active.
• In these scenarios, you’ll need more in-depth knowledge of Office 365 licensing, Azure Active Directory (Azure AD) configurations, or advanced policy settings.
• Always verify offline availability settings for critical documents you might need.

Confirm your subscription status and sign in with the correct Microsoft account. Run the Activation Troubleshooter, accessible online or via your app settings. Verify your device is connected to the internet and your payment details are current for renewal. Remove and re-add your Office account within the app for reconnection. Start by verifying your subscription status to ensure it’s still active.



Troubleshooting Office 365 sign-in or activation issues can be straightforward if you approach the problem methodically. By verifying the basics—correct credentials, valid license assignments, and disable faulty add-ins in Outlook stable network access—you’ll often fix the issue without delving into more complex solutions. Clearing cached credentials, running a repair, or using the Microsoft Support and Recovery Assistant (SaRA) can also address common local device issues. Verify that you’re logged into the correct Microsoft account both in OneDrive and Office apps.

Microsoft 365 troubleshooters

If syncing is paused, resume it from the OneDrive system tray icon. Double-check your internet connection, as OneDrive requires an active network to repair corrupted OST in Outlook sync files properly. For a larger cache of files, clear up local storage to ensure uninterrupted access.