Windows Defender Error loading type library/DLL

Windows security allows you to manage quarantined items and exclusions. Doing so, if you receive an error saying Windows Defender Antivirus Error Loading Type / DLL Library, Click Help for more information about this problem, Error Code 0x80029c4athen this post will show you how to fix this error. Because of this error, you will not be able to see the list of quarantined and allowed items.

Windows Defender Error When Loading Type / DLL Library

If you are using Windows 10 v 1709, you should know that the name used by Microsoft to call Windows Defender is now called Windows Security. According to forum users, the error code seems to occur for those who are trying to launch Windows Defender, but with the help of an old shortcut used for Windows Defender Security Center.

Let's be specific. When you use the old shortcut, you launch an older version that is still supported or available on your computer.

C:Program FilesWindows DefenderMSASCui.exe

This file is no longer available in Windows 10 v1903.

There are two ways to solve this problem:

1) Run MSASCui.exe with Administrator Privileges

• Navigate to the C: Program Files Windows Defender directory.
• Right-click MSASCui.exe and select Run As Administrator.

It will launch Windows Defender Security Center and you should be able to manage your quarantined list. When you upgrade to the new version of Windows, this shortcut will stop working.

2) Use the new Windows security

• Type Windows Security at the beginning
• When it appears, drag it to the desktop or right-click and add it to the taskbar.
• Now, when you launch it, the new interface will open and work correctly without error.

This bug was also identified by Microsoft and one of the engineers left a comment in the comments center. It said:

This error can occur in the Windows 10 Fall Creators (version 1709) update if you use a shortcut to open Windows Defender and this shortcut was created when using Windows 10 version 1703. Windows Defender Antivirus has been updated with Windows 10 Creators. Update (version 1703), designed to be easier to use and provide a complete security experience. However, the old user interface of version 1703 is no longer supported in version 1709. To resolve the error, we recommend that you remove the shortcuts that you previously used, to launch Windows Defender and create a new shortcut in Windows 10 version 1709.

We hope that the solutions worked for you and that you could use them again. You must upgrade your Windows 10 to the latest available version or switch to the new interface and remove this error.