Member Not Found Error On Escalation

I made an HTML e-mail template and am applying that in various portions of the workflow. I recieved an error today in one of the escalation which was "Member Not Found". In the error manager I tried to redirect the e-mail to me also tried the Try catch statements but it will not even create an exception for the error. Any thoughts on why it would do that?
All the help will be greatly appreciated. It works fine for most of the escalations and other places where I am using the same e-mail verbaige in html format.