This blog discusses a number of Microsoft technologies, including Microsoft Dynamics CRM, Microsoft Office Project Server, Microsoft SharePoint Server and others.
HTTP Error 500.0 – Internal Server Error
Calling LoadLibraryEx on ISAPI filter “C:\Program Files\Microsoft Dynamics CRM Server\Server\bin\DefaultAddonFilter.dll” failed.
The CRM application server was hosted on a 64-bit server with 8GB memory, running Windows Server 2008 R2, IIS7.
The cause of this problem was related to missing Microsoft Visual C++ 2008 SP1 runtime components. After installing these component, CRM worked like a charm.
Below are links to the runtime libraries in case others run into this issue:
Other Microsoft Sites
I'm a Customer
I'm a Partner
Follow Microsoft Dynamics