Unrecognized escape sequence (error CS1009)

A common case for this error is using the backslash character in a file name. Replace “\” with “\\” or use “@” prefix for the literal as shown below

Error

StreamWriter SW = new StreamWriter("c:\shasurdata\forblogger\Sample.txt");

Corrected

StreamWriter SW = new StreamWriter("c:\\shasurdata\\forblogger\\Sample.txt");

Or

StreamWriter SW = new StreamWriter(@"c:\shasurdata\forblogger\Sample.txt");