I'm encountering a very strange issue while debugging a unit test. If I debug the unit test (ctrl+r ctrl+t) I am getting an uncaught exception. If I just run the unit test (ctrl+r t) I do not get this exception.

The uncaught exception is a **NHibernate.ByteCode.ProxyFactoryFactoryNotConfiguredException.**

Stack trace: 

```
at NHibernate.Bytecode.AbstractBytecodeProvider.get_ProxyFactoryFactory() in d:\CSharp\NH\NH\nhibernate\src\NHibernate\Bytecode\AbstractBytecodeProvider.cs:line 32
at NHibernate.Validator.Util.NHibernateHelper.IsProxyFactoryConfigurated()

```

I used .Net Reflector to look at the assembly that defines this method (NHibernate.Validator ... it's open source) and here is the method that "throws" the exception: 

```
public static bool IsProxyFactoryConfigurated()
{
    try
    {
        IProxyFactoryFactory proxyFactoryFactory = Environment.BytecodeProvider.ProxyFactoryFactory;
        return true;
    }
    catch (ProxyFactoryFactoryNotConfiguredException)
    {
        return false;
    }
}

```

How can this exception not be caught by that Try Catch block?