It’s most likely because IE no longer starts apps that use managed browser hosting controls, like in the .NET Framework 1.1 and 2.0. You can get IE11 to use managed browser hosting controls again, by:
For x86 systems or for 32-bit processes on x64 systems: Go to the HKLM\\SOFTWARE\\MICROSOFT\\.NETFramework registry key and change the EnableIEHosting value to 1.
For x64 systems or for 64-bit processes on x64 systems: Go to the HKLM\\SOFTWARE\\Wow6432Node\\.NETFramework registry key and change the EnableIEHosting value to 1.
For more information, see the Web Applications section of the Application Compatibility in the .NET Framework 4.5 page.