If the issue persists, repeat the process and choose Online Repair. This process replaces damaged core files without removing your data or customizations. 21Vianet also expect customer to collaborate at reasonable level accordingly.

⃣ Reset Browser Cookies & Cache

21Vianet understands that receiving timely technical support from qualified professionals is a key aspect of cloud services. Equally important is the critical role that the customer’s IT department plays in the support of its users. The Microsoft 365 operated by 21Vianet technical support team troubleshoots only those issues that are related to Microsoft 365 operated by 21Vianet. Incorrect system time can break your connection to Microsoft’s authentication servers. Always enable Set time automatically and select the correct region in your Windows settings.

Microsoft 365 Apps Crashing After Update — Step-by-Step Repair Guide

• Have your Microsoft 365 apps suddenly started crashing after a recent Windows or Office update?
• Incorrect system time can break your connection to Microsoft’s authentication servers.
• We’ll walk you through step-by-step solutions for Office, Outlook, or Teams sign-in errors.
• Explore learning tools to collaborate on projects together and independently, all in one place.

For iPhone users, reinstalling Outlook or updating to the latest iOS often resolves stuck sign-in loops instantly. Many users have both personal Microsoft accounts (e.g., diagnose office Activation conflicts Outlook.com) and work/school Office 365 accounts. If both are signed in simultaneously, the system can confuse the authentication path.

? Fix Office 365 Login Issues on Mobile

If all else fails, uninstall Microsoft 365 completely, remove remaining registry traces using the Office Uninstall Support Tool, and reinstall it fresh. This guarantees clean configuration files and resolves deep-level connection status shows disconnected corruption issues. Partial updates often break compatibility between Windows libraries and Office binaries.

Step 2 – Update Outlook and Office 365

This ensures that the system-wide search index service is active and linked to Office 365 apps. Then, navigate to File → Options → Add-ins, and disable all non-Microsoft add-ins. If your country/region isn’t listed, select a neighboring country/region or dial the United States support phone number. For a smoother support experience, we recommend that you open separate support requests for each issue. You must have at least one subscription bought through modern authentication troubleshooting Microsoft to access Microsoft support. The steps to access the repair tool vary depending on your operating system.

Repair Outlook OST File Not Working in Office 365 – Complete Fix (

Explore learning tools to collaborate on projects together and independently, all in one place. Create equitable learning environments that help students develop knowledge with familiar apps essential to both academic and future career success. If login issues are still persisting, our experts can assist you live via WhatsApp. We’ll walk you through step-by-step solutions for Office, Outlook, or Teams sign-in errors.