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 repair corrupted OST in Outlook 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 Microsoft Outlook Email Repair Tool Online to repeated sign-in prompts or activation failures.

Recover your account

The Microsoft Support and Recovery Assistant can automate fixes for common error codes. The "Unlicensed Product" error usually indicates an inactive or unlinked subscription. Confirm your subscription status and sign in with the correct Microsoft account. Run the Activation Troubleshooter, accessible online or via your app settings.

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 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.
• Run the Activation Troubleshooter, accessible online or via your app settings.

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

Look up the error code on the official Microsoft site for tailored steps. Outlook data file cannot be accessed Check if your system meets the Microsoft 365 installation prerequisites. For codes linked to storage limitations, free up disk space or install on an external drive.