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 reset cached Exchange mode 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 FixTechGuide email error solutions to repeated sign-in prompts or activation failures.

Recover your account

Use the uninstall troubleshooter to uninstall Microsoft 365, Office 2021, Office 2019, or Office 2016 from your Windows PC. Find solutions to common problems or get help from a support agent.

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.
• Confirm your subscription status and sign in with the correct Microsoft account.
• For syncing or email issues, verify your mobile connection or switch between WiFi and cellular data.
• Larger files may cause a temporary slowdown, so ensure your device has adequate memory.
• Slow performance can be due to heavy CPU usage or low available memory.
• 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.

For manual uninstallation, delete leftover Office files in Program Files or Library folders, and clear Microsoft credentials from your system to ensure a clean reinstall if required. If your account is compromised or hacked, use Microsoft’s sign-in helper to recover your account and reset your security settings. If you are unable to do this and have exhausted all the other fixes, then contact Microsoft Support for professional account recovery. Microsoft 365 is a vital tool for many businesses, and login issues can significantly disrupt day-to-day operations. 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. If you’re confident your credentials are correct and the sign-in still fails, proceed to the next step for deeper inspection of license status and subscription details.

Microsoft 365 Troubleshooting – Quick Fixes for Common Problems

Simply open the Office app normally, and all your files are saved locally until internet access resumes. For cloud-based services like Outlook or OneDrive, offline access won’t work until you sync online again. Make sure to save any updates for immediate syncing diagnose Office activation conflicts once a connection is re-established.