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. If this doesn’t work, reset the credentials in your Windows Credential Manager how to fix Outlook not opening today 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. Yes, Microsoft 365 works offline for most apps like Word and Excel.

How do I fix the ‘Product Activation Failed’ error in Microsoft 365?

Additionally, ensure you’ve installed all available updates, as performance improvements are often included in patches. Regularly cleaning up your hard drive or upgrading hardware like RAM can also enhance performance. If you’ve tried all these steps and still can’t resolve the sign-in or activation errors, you may need more advanced troubleshooting. Completing the above steps resolves a large majority of Outlook OST Vs PST Repair typical sign-in and activation problems.

Recover your account

If the issue persists, Microsoft has created a dedicated tool called Microsoft Support and Recovery Assistant (SaRA) to automate many troubleshooting tasks. The tool will ask you to enter the email address or mobile phone number you're trying to sign in with and check the detailsyou provide. If we detect a problem with your account, we'll tell you what you need to do to solve the problem.

3 Step 3: Verify Network Connectivity and Firewall Settings

• If freezing persists, reinstall the app using files downloaded from your account dashboard to rule out bugs.
• If you can't sign into your Microsoft account, most issues can be identified by our sign-in helper tool.
• Sometimes cached credentials on your device or a corrupted Office profile can lead to repeated sign-in prompts or activation failures.
• Below is a structured approach to diagnosing and resolving Office 365 sign-in or activation errors.
• If we don't detect any problem, we'll guide you through how you can help yourself.
• If these connections are disrupted, sign-in and activation will fail.
• Regularly cleaning up your hard drive or upgrading hardware like RAM can also enhance performance.

You might find it simple, but the most common cause of login failure is entering the wrong username and password combinations. Below is a structured approach to diagnosing and resolving Office 365 sign-in or activation errors. Start with the basics and move toward more advanced methods only if necessary.

Microsoft 365 Troubleshooting – Quick Fixes for Common Problems

If you encounter this error – Sorry, we are having temporary server issues, then chances are that the issue lies at Microsoft’s end. Alternatively, you can use the browser’s incognito mode or private mode to check if the issue persists. If you would like to ask me another question in the future, you can add me as a favorite Expert. You'll have the option to do that on your \"My Questions\" page if you choose to rate our interaction or you can request me by name if you wish. You'll have the option to do that on your "My Office 365 sync problems and login fixes Questions" page if you choose to rate our interaction or you can request me by name if you wish.