I don't understand why this Statemant runs in SQLServer 2008

raiserror 22004 'The system cannot find the file specified.'

I have change it in SQLServer 2012 to

raiserror (N'22004 The system cannot...

After changing to

if@exists = 0

begin

raiserror (22004, 'The system cannot find the file specified.')

return2

end

I got the following error:

Msg 102, Level 15, State 1, Procedure sp_SDMS_getfiledetails, Line 34

Incorrect syntax near 'The...