A connectivity bug is preventing certain apps from connecting to the Internet on some Windows 10 computers. Find out which machines are affected and how to get rid of it.

To minimize the spread of COVID-19, many companies are having their employees work from home. However, that might prove challenging, thanks to a connectivity bug in Windows 10. The bug is preventing certain Microsoft productivity apps (e.g., Office, Outlook) from connecting to the Internet.

The Affected Computers

The connectivity bug affects Windows 10 computers that use a proxy and have the February 27, 2020 (KB4535996) cumulative update (or any of the three subsequent cumulative updates) installed. The problem is most prevalent when people use a virtual private network (VPN). Companies often have remote employees use a VPN to ensure a more secure connection.

The connectivity bug can cause two types of problems:

  • Applications that use the Windows HTTP Services (WinHTTP) or Windows Internet (WinINet) application programming interface might not be able to connect to the Internet. The affected apps include Microsoft Teams, Office, Office 365, Outlook, Internet Explorer 11, and some Microsoft Edge versions.
  • The Network Connectivity Status Indicator in Windows 10’s notification area might show that there is limited or no Internet connection when that is not the case.

This connectivity bug also affects Windows Server 2019 (Long Term Servicing Channel) and Windows Server versions 1709 through 1909 (Semi-Annual Channel).

How to Get Rid of the Bug

Microsoft has released an optional patch —March 30, 2020 update (KB4554364) — to fix this bug in Windows 10. (Patches are also available for the various Windows Server versions.) However, Microsoft recommends that you only install this update on machines affected by this issue.

The KB4554364 patch is not available through Windows Update. It needs to be downloaded from the Microsoft Update Catalog and manually installed. If any of your business’s remote Windows 10 computers are experiencing the connectivity issues described here, we can take care of installing the patch for you.

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