Quick question.
Can I recover a lost .cs file using RedGate Reflector ?
My assembly is a debug version
If you open .NET assembly in Reflector, you should be able to switch which language Reflector uses to display the code e.g. IL, VB.NET, C#. There is a dropdown list on the UI menu bar with this selection of languages.
As long as you have all the required external libraries and references, you should be able to copy the C# code form Reflector and try to rebuild it.