WPF browser-hosted applications (XBAPs) may crash during start-up

This article helps you resolve the problem where WPF XBAPs may crash during start-up.

Original product version:   Microsoft .NET Framework 3.5 Service Pack 1
Original KB number:   972928

Symptom

WPF XBAPs may crash during start-up.

Cause

One cause of this problem is that system-level interface registrations are broken. In particular, registrations for the following interfaces may be missing:

  • IID_IWebBrowser2
  • IID_IShellBrowser

This can be because of failed installations or upgrades, or malware infections.

Resolution

Re-register the broken interfaces by running the following commands:

regsvr32 %SystemRoot%\System32\actxprxy.dll
regsvr32 "%ProgramFiles%\Internet Explorer\ieproxy.dll"

On 64-bit Windows, also run the following commands:

regsvr32 %SystemRoot%\SysWOW64\actxprxy.dll
regsvr32 "%ProgramFiles(x86)%\Internet Explorer\ieproxy.dll"

On Windows XP and Windows Server 2003, these commands need to be run from a user account with administrative privileges on the machine.

On Windows Vista or later, these commands need to be run elevated. Select Start > All Programs > Accessories. Right-click Command Prompt and select Run as Administrator. At the command prompt, run the commands.

Check whether the problem is fixed. If the problem is fixed, you're finished with this section. If the problem isn't fixed, you can contact support.