Why would Visual Studio 2010 say it can't show a variable during debug?

Question

In Visual Studio 2010 sometimes when I want to get the value of a variable while debugging, it tells me that it \"does not exist in

Answer 1

Is GetListOfFileNames() deferring execution? Try tacking .ToList() on it.

Answer 2

Hazarding a guess..

Could it be that your running in Release mode and the variable has been optimized out? Once you actually use the value, then it no longer can optimize the value out?