Windows 10 KB5004760 emergency update fixes PDF opening issue

Microsoft has released an optional out-of-band update for all supported Windows 10 versions to address an issue preventing customers from opening PDF documents using some applications.

The KB5004760 emergency update is available for devices running client editions of Windows 10 versions 2004, 20H2, and 21H1, as well as Windows Server versions 2004 and 20H2.

“An out-of-band optional update is now available on the Microsoft Update Catalog to address an issue in which Internet Explorer 11 and apps using the WebBrowser control might fail to open PDFs,” the company says.

“Additionally, a PDF might render as just a gray background when using the Adobe Acrobat plug-in,” Microsoft adds in a support article.

Internet Explorer users are only affected by this bug if they toggle on “Enable 64-bit Processes for Enhanced Protected Mode” is enabled in the Advanced tab in Internet Options.

Because KB5004760 is a cumulative update, you will not have to deploy any previous update before installing it.

You can manually download it and install it from the Microsoft Update Catalog. Admins can also import it into Windows Server Update Services (WSUS) manually.

Workaround also available

Microsoft also provides workaround measures for impacted customers who cannot immediately install  the KB5004760 cumulative update.

To make sure that you can open PDFs on your device even though it’s been affected by this bug, you can:

• Open the PDF file directly in Adobe Acrobat instead of within IE11 or the affected app.
• For IE11 only: Disable the setting in the Advanced tab of Internet Options called Enable 64-bit Processes for Enhanced Protected Mode.

In related news, Microsoft has released the first Windows 10 build without the Internet Explorer web browser to Windows Insiders in the Dev Channel just a little over a month ago.

The Windows 11 announcement also said that Internet Explorer will be disabled in Windows 11 as the new Chromium-based Microsoft Edge now includes the IE Mode feature.