Obsolescence WARNING
Web deployment of windows forms control as ActiveX components is an ancient
technology which is no longer supported by Atalasoft.. This article was an
attempt to help customers who are still struggling to migrate off this type of
solution to keep things running just a bit longer. This article is here for
reference, but support will no longer provide any additional assistance on this
matter. The supported solution is to move to a modern control such as our
WingScan web based scanning
INFO: WingScan Whitepaper - Getting Started with Web Scanning (11.1 version)
Main Article Content
Some customers have reported that their Managed browser hosting controls
(.NET 2.0 winforms controls embedded in a user control for IE) suddenly stopped
working.
Further investigation found that this occurred after applying certain
security patches related to .NET 4.5 (such as those in MS KB 2858725)
In their page on Application
Compatibility in .NET 4.5, Microsoft explicitly states the following under
"Web Applications":
Feature: Managed browser hosting controls from the .NET Framework 1.1
and 2.0
Change: Hosting these controls is blocked in Internet
Explorer.
Impact: Internet Explorer will fail to launch an application
that uses managed browser hosting controls.
The previous behavior can be restored by setting the EnableIEHosting value of
the registry subkey HKLM/SOFTWARE/MICROSOFT/.NETFramework to 1 for x86 systems
and for 32-bit processes on x64 systems, and by setting the EnableIEHosting
value of the registry subkey HKLM/SOFTWARE/Wow6432Node/.NETFramework to 1 for
64-bit processes on x64 systems.
So to sum this up: MS is explicitly blocking embedded Managed Browser Hosting
Controls. this is being done for security purposes. There is every possibility
that a future update could remove even the ability to override this block.
Atalasoft support strongly recommends that if you're still maintaining a user
control that uses our .NET 2.0 winforms components, that you immediately begin
the process of replacing that functionality using our classic ASP.NET controls
(WebImageViewer, WebAnnotationViewer / WebThumbnailViewer) or our new ASP.NET
controls (WebDocumentViewer /WebDocumentThumbnailer).
If you were using DotTwain user control, please look into our WingScan
components for web based scanning.
Original Article:
Q10389 - FIX: Embedded .NET User Controls Suddenly Stop Working in IE