We can help you find a solution or connect you to technical support. This restores missing or corrupted Office components that affect search indexing. If a Microsoft 365 application such as Word or Excel isn't working correctly, sometimes restarting it will fix the problem. Download the tool from Microsoft and run the Outlook diagnostic to auto-detect server and account issues.

⃣ 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

• With Microsoft 365, you can designate several types of administrators who serve different functions.
• Many users have both personal Microsoft accounts (e.g., Outlook.com) and work/school Office 365 accounts.
• This process replaces damaged core files without removing your data or customizations.
• Then, navigate to File → Options → Add-ins, and disable all non-Microsoft add-ins.
• Microsoft 365 Basic now comes with 100GB of cloud storage, secure photo and file storage, secure ad-free email, and technical support.

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., how to fix Outlook not opening today 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

21Vianet assigns a severity level to a case when it’s opened, based on an assessment of the issue type and customer impact. Examples of issue types and severity levels are shown in the following table. Authorized administrators can use the Microsoft 365 operated disable faulty add-ins in Outlook by 21Vianet portal to submit service requests online and access support telephone numbers.

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 send/receive error 0x800CCC0E fix to Control Panel → Programs and Features, select Microsoft 365, and click Change → Quick Repair.

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

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.