If your column data type is 'text' then you will get an error message as
Msg 8116, Level 16, State 1, Line 2 Argument data type text is invalid for argument 1 of replace function.
In this case you need to cast the text as nvarchar and then replace
SELECT REPLACE(REPLACE(cast(@str as nvarchar(max)), CHAR(13), ''), CHAR(10), '')