In Sandbox:- Create a case via 'Email To Case'.
However, when user tries to answer via email(using service cloud console), following error is coming. Strange enough, case can be answered via 'Portal'.
"The data you were trying to access could not be found.
It may be due to another user deleting the data or a system error.
If you know the data is not deleted but cannot access it, please look at our support page."
What can be possible reason?