A: 

It might be a namespace issue. Try adding namespace:: before your symbol in the debugger watch window, if the symbols you're trying to watch are inside a namespace.

Adam Rosenfield
+1  A: 

Is the module compiled with optimizations turned on?

If so, the vScenarioDescription may not actually not actually exist in memory. In VS2008 I don't get a messagebox error, the variable simply doesn't show up in the 'Locals' window, and if I try to watch it, the Watch windows says:

CXX0017: Error: symbol "name" not found

I don't have VS2005 installed anymore so I don't know if it pops up a messagebox like you're seeing or behaves like VS2008.

Michael Burr
+1  A: 

From top of my head, there can be several:

  • The symbol information might be corrupted. Try doing a clean rebuild of the whole solution.
  • If you have multiple projects in the solution, check the Configuration Manager (Build menu) if all of them are in the Debug setting. Say, some DLLs or some components might be in the release mode that does not include any debug info.
  • If you are using some 3rd party libraries (DLL), they might have no debug info at all.
Ignas Limanauskas