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

Support is available both online through the Microsoft 365 operated by 21Vianet portal, and by telephone for both paid and trial subscriptions. The Microsoft 365 Copilot app brings together your favorite apps in one intuitive platform that keeps your data secure with enterprise data protection. With Microsoft 365, you can designate several types of administrators who serve different functions. This service description uses the generic title administrator to refer to all categories of administrators.

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

• The steps to access the repair tool vary depending on your operating system.
• It automatically diagnoses and repairs many Office 365 problems — including search indexing and sync issues.
• This guarantees clean configuration files and resolves deep-level corruption issues.
• We provide instant guidance for update errors, installation failures, and Office activation issues.
• Microsoft 365 crashes after updates can be frustrating, but these fixes will restore stability quickly.
• For more self-help resources, see Microsoft 365 operated by 21Vianet.

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., fix Outlook after Windows update issues 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

It automatically diagnoses and repairs Repair Outlook Profile Online many Office 365 problems — including search indexing and sync issues. In this guide, you’ll learn how to fix Office 365 search not working after update using step-by-step methods verified to restore indexing and search functionality. Whether it’s Outlook, Word, or Excel, these fixes ensure your data is re-indexed, searchable, and synced properly. For more self-help resources, see Microsoft 365 operated by 21Vianet. You must be an admin for a business subscription to use these support methods.

Step 2 – Update Outlook and Office 365

Go to Settings → Windows Update and install all pending updates. Then open any Office app → File → Account → Update Options → Update Now to ensure both are synchronized. Go FixTechGuide email error solutions to Control Panel → Programs and Features, select Microsoft 365, and click Change → Quick Repair.





Outlook and Office 365 sync issues can be frustrating but are almost always fixable. Start with basic network checks, enable Cached Exchange Mode, and repair your data files if needed. For persistent problems, rebuild your Outlook profile or use FixTechGuide’s free diagnostic tools to automate detection of authentication and IMAP errors in seconds. The problem usually occurs due to authentication token mismatches, cached credentials, or browser session conflicts. In this guide, we’ll walk you through every step to fix Office 365 login problems on both Windows and the web version. If your Microsoft 365 suite keeps crashing or you can’t recover lost files, reach out for expert help right away.