Use the Microsoft 365 network connectivity test to measure connectivity between your device and the internet, and from there to Microsoft’s network. Use the MIcrosoft 365 inventory scan troubleshooter to generate either a normal Outlook stuck updating folders solution or full scan report of your computer and installed Microsoft 365 applications. Use the Microsoft 365 sign-in troubleshooter to help resolve sign-in issues encountered with Microsoft 365. If you can't sign into your Microsoft account, most issues can be identified by our sign-in helper tool.

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

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. Browser or app issues, like outdated software or cached data, can also interfere; try clearing your cache or switching solve Office 365 mailbox sync delays browsers. Troubleshooting Office 365 sign-in or activation issues can be straightforward if you approach the problem methodically.

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

• Microsoft 365 is a vital tool for many businesses, and login issues can significantly disrupt day-to-day operations.
• If we detect a problem with your account, we'll tell you what you need to do to solve the problem.
• Close unused tabs, background processes, or applications to free up system resources.
• You have to follow a systematic approach while dealing with Microsoft 365 login issues.
• Perform a quick repair via "Programs and Features" to optimize 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

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 flush DNS and re-sync Outlook once a connection is re-established.