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 recreate Outlook profile step by step 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?

If we don't detect any problem, we'll guide you through how you can help yourself. Being a Microsoft 365 user, if you have encountered an error while logging into your account, you are not alone. Remember, if all else fails, reaching out to Microsoft Support directly or using their official support documentation can provide tailored assistance for complex organizational setups. With the right planning and knowledge, nearly all sign-in and activation troubles can be resolved quickly and efficiently. Sometimes cached credentials on your device or a corrupted Office profile can lead modern authentication troubleshooting to repeated sign-in prompts or activation failures.

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 details you 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 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.
• Start with the basics and move toward more advanced methods only if necessary.
• If your account is locked due to multiple unsuccessful login attempts, wait for the lockout period to end.
• In many cases, performing simple checks—like verifying correct usernames and valid licensing—will resolve the issue quickly.

Follow this guide to ensure a smooth and error-free Microsoft 365 login experience. Additionally, check out the above-listed security best practices and keep your team members aware of common troubleshooting tips. Troubleshooting Microsoft 365 login issues often requires a methodical approach, starting with basic checks and escalating to more complex troubleshooting if needed. Remember, proactive management and regular reviews of your IT infrastructure can prevent many common issues, keeping your business operations running smoothly. Make sure your phone’s operating system is supported by Microsoft 365.

Microsoft 365 Troubleshooting – Quick Fixes for Common Problems

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. diagnose Office activation conflicts 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.