This is a bug that hits the csharp shell (and probably the underlying Mono.CSharp.Evaluator) only when running on MSFT .NET, not when running on Mono.
It's triggered when loading a DLL from the Math.NET numerics project (can download binaries here: http://mathnetnumerics.codeplex.com/downloads/get/616759). Unpack binaries to C:\MathNet.Numerics-126.96.36.199, and unblock the MathNet.Numerics.dll file (right click the file, click the Unblock button at bottom right). Then try the following:
First launch csharp shell using Mono 3.0.3 with:
"C:\Program Files (x86)\Mono-3.0.3\bin\csharp.bat"
Then run following in shell:
var standard_normal = new MathNet.Numerics.Distributions.Normal();
This will provide the expected output:
Normal(Mean = 0, StdDev = 1)
Then launch csharp shell using .NET framework with:
"C:\Program Files (x86)\Mono-3.0.3\lib\mono\4.5\csharp.exe"
Then run the same lines in the shell, and on the last line you'll get:
System.IO.FileNotFoundException: Could not load file or assembly 'MathNet.Numerics, Version=188.8.131.52, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified. File name: 'MathNet.Numerics, Version=184.108.40.206, Culture=neutral, PublicKeyToken=null'
at <InteractiveExpressionClass>.Host(Object& $retval)
at Mono.CSharp.Evaluator.Evaluate(String input, Object& result, Boolean& result_set)
at Mono.CSharpShell.Evaluate(String input)
WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
This is especially odd, because you can then run
from x in AppDomain.CurrentDomain.GetAssemblies() where x.GetName().Name == "MathNet.Numerics" select x.GetName().FullName
you can see that .NET thinks it's already loaded the assembly that it just couldn't find.
Still an issue in Mono 3.0.6.
Still an issue in Mono 3.0.9.
Still an issue in Mono 3.2.3.