Steps to Reproduce the Behavior

1. Create a new Microsoft Visual C++ Win32 project named fnTest.
2. On the Application Settings tab, change Application type to DLL.
3. Paste the following code in Fntest.cpp:

   extern "C"
   {
   
   	__declspec(dllexport) double fnTest(double d)
   	{
   		return d;
   	}
   }
   					

4. Compile the project and get the Fntest.dll file.
5. Create a new Microsoft Visual Basic .NET Console Application project.
6. Paste the following code in Module1.vb:

   Module Module1
   
       Declare Function fnTest Lib "fnTest.dll" (ByVal d As Date) As Date
   
       Sub Main()
           Dim m As Date
           m = fnTest(System.DateTime.Now)
           System.Console.WriteLine(m)
       End Sub
   
   End Module
   					

7. Compile the project.
8. Put the fnTest.dll in the same folder as the executable (.exe) file, and then run the .exe file. You receive the exception error message.
9. To work around this problem, use the following code:

   Module Module1
   
       Declare Function fnTest Lib "fnTest.dll" (ByVal d As Date) As Double
   
       Sub Main()
           Dim m As Double
           Dim d As Date
           m = fnTest(System.DateTime.Now)
           d = DateTime.FromOADate(m)
           System.Console.WriteLine(d)
       End Sub
   
   End Module
   					

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