Third-party products that rely on BHOs or toolbars break in Internet Explorer 11

Warning

The retired, out-of-support Internet Explorer 11 desktop application has been permanently disabled through a Microsoft Edge update on certain versions of Windows 10. For more information, see Internet Explorer 11 desktop app retirement FAQ.

This article provides the workaround to make sure the logic of third-party products cannot break due to Browser Helper Objects (BHOs) or toolbars.

Original product version:   Internet Explorer 11
Original KB number:   3058703

Symptoms

When you develop a third-party product that relies on a Browser Helper Object (BHO) or a toolbar, the product cannot detect whether a newly created tab is a virtual tab. This behavior occurs when the virtual tab is not visible in Internet Explorer 11.

Cause

This issue occurs because non-visible virtual tabs that are created in Internet Explorer 11 may break the logic of the product, and the product cannot detect whether a tab is virtual or not.

Note

Virtual tabs are heavily used in Internet Explorer 11. You may encounter this issue if you just want to create resources or perform actions only when a tab is visible.

Workaround

To work around this issue, use certain techniques, such as relying on a secondary thread to check the window state about 1 second after the product obtains the handle.