Using string.Replace with speical characters

Hello,

I try to replace "\r" or "\n" from my exception message string and write it to the workflow history.

Whenever I try to replace these characters, the workflow get suspended. 

My sample exception is sth like: "System.DivideByZeroException: Attempted to divide by zero.\r\n at SharePoint..."

string.Replace works fine for any letter or number, but not with speical characters. Replacing special characters breaks my workflow.

Anybody knows why / has a solution for this?

Thank you.