This dialog box appears when you have made changes to native code that Edit and Continue could not immediately apply. As a result, some native code in the current stack frame is now out of date, that is, stale. For more information, see How to: Work with Stale Code.
Don't show me this dialog again
If you select this check box, Edit and Continue will apply code changes without asking permission in the future. You can turn this warning on again by going to the Options dialog box, opening the Debugging Folder, clicking the Edit and Continue page, and selecting Warn about stale code.