You can feel free to contact our experts, as they are available 24X7 for solving your issues. If your subscription has expired, your account is disabled, or your IT admin has blocked your account, in all these cases, you would not be able to log in to your account. Use the Microsoft 365 setup troubleshooter to install Microsoft 365, Office 2021, Office 2019, or Office 2016 on your Windows PC. Use the uninstall troubleshooter to uninstall Microsoft 365, Office 2021, Office 2019, or Office 2016 from your Windows PC.

Common Causes of Office 365 Sign-In and Activation Issues

Use the Microsoft 365 activation troubleshooter to resolve Microsoft 365 subscription activation issues. Slow performance can be due to heavy CPU usage or low available memory. Close unused tabs, background processes, or applications to free up system resources. Additionally, ensure you’ve installed all available updates, as performance improvements are often included in patches.

I can't sign in to my Microsoft account

In this comprehensive guide—KB113—we’ll explore the most common causes of Office 365 sign-in and activation issues. We’ll then walk you through a practical, step-by-step troubleshooting methodology. Combine these best practices with ongoing training and proactive license management, and you’ll be well on your way to a stable, secure Office 365 environment. Sometimes, an expired license or outdated credentials are the culprit. Other times, it might be network problems, conflicting versions of Office, or organizational security policies that block the authentication process.

What should I do if updates for Microsoft 365 apps fail to install?

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. If syncing is paused, resume it from the OneDrive system tray icon.

Frequently asked questions

If this doesn’t work, reset mailbox not updating on IMAP the credentials in your Windows Credential Manager or contact Microsoft support for further assistance. Despite its robust feature set and user-friendly design, it’s not uncommon for end users and IT professionals to encounter sign-in and activation issues. If you or your employees can’t sign in to Office 365, or if the applications repeatedly prompt for activation, productivity can grind to a halt.

• Clearing cached credentials, running a repair, or using the Microsoft Support and Recovery Assistant (SaRA) can also address common local device issues.
• Use the Microsoft 365 network connectivity test to measure connectivity between your device and the internet, and from there to Microsoft’s network.
• In this guide, we will take an in-depth look at troubleshooting and resolving common Microsoft 365 login problems so you can keep your business running smoothly.
• Completing the above steps resolves a large majority of typical sign-in and activation problems.
• Use the Microsoft 365 setup troubleshooter to install Microsoft 365, Office 2021, Office 2019, or Office 2016 on your Windows PC.

It can vary from 1 to 30 minutes, depending on the number of failed attempts you have performed. Once the waiting period is Fix Outlook and Office 365 Errors 2025 over, try logging in again with the right credentials. In these scenarios, you’ll need more in-depth knowledge of Office 365 licensing, Azure Active Directory (Azure AD) configurations, or advanced policy settings.



Sometimes cached credentials on your device or 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. 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 you’re unable to sign in to your Microsoft 365 account, ensure you’re using the correct email and password. Locked accounts, due to multiple failed attempts, may require waiting or following unlock instructions. Check your internet connection, as weak connectivity can cause issues. For work or school accounts, confirm with your organization that your account is active.

Remove and rebuild Outlook data file quickly re-add your Office account within the app for reconnection. Start by verifying your subscription status to ensure it’s still active. Go to any Office app and ensure you’re signed in with the same Microsoft account linked to your license. Remove and re-add your account under the "Account" settings of the app if needed.