I have seen a couple of threads on these forums that seem to indicate a potential issue accessing shared memory from within IIS 8 on Windows Server 2012. I appear to be having a similar issue and I'd like to determine if there is any known limitations or configuration requirements to support this.
The application in question is an ASP.NET 4.0 MVC application which is using P/Invoke interop to communicate with a native 64-bit library. That library opens a handle to shared memory initially created by a separate service. Attempting to read that shared memory is causing an access violation exception in the unmanaged code. However, a 64-bit .NET console application using the same library on the same Windows Server 2012 machine is having no such issues, nor is this same exact web application when installed on Windows Server 2008.
Note that the access violation exception occurs in both IIS 8 and IIS Express 8 on Windows 8 and Windows Server 2012, but not in IIS 7.5 or IIS Express 8 on Windows 7 or Windows Server 2008.