However, if the administrator is unable to resolve issues with the help of self-service support resources, they should Contact support. Technical support for Microsoft 365 operated by 21Vianet subscriptions provides assistance with basic installation, setup, and general technical usage. If you’re a volume licensing admin but are unable to access the admin center, you can create an online support request. With every subscription of Microsoft 365 operated by 21Vianet, 21Vianet support provides technical, presales, billing, and subscription support. Have your Microsoft 365 apps suddenly started crashing after a recent Windows or Office update? Many users experience random application freezes, launch errors, and constant crashes after installing new patches or cumulative updates.

⃣ 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

• With Microsoft 365, you can designate several types of administrators who serve different functions.
• If your Microsoft 365 suite keeps crashing or you can’t recover lost files, reach out for expert help right away.
• 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.
• You must have at least one subscription bought through Microsoft to access Microsoft support.
• 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., Exchange connectivity diagnostic 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 Outlook Stuck on Synchronizing Folders by 21Vianet portal to submit service requests online and access support telephone numbers.

Step 2 – Update Outlook and Office 365

We provide instant guidance for update errors, installation failures, troubleshoot Outlook synchronizing folders error and Office activation issues. When Office 365 search stops working after updates, it’s usually a minor indexing or cache issue — not a major fault. Following the steps above should restore your search functionality quickly. For advanced troubleshooting, FixTechGuide offers remote support to restore performance and indexing accuracy for Outlook and other Office apps. Microsoft 365 crashes after updates can be frustrating, but these fixes will restore stability quickly.





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.