An error that you would only encounter if using software instead of hardware serial. Almost "everyone" uses secondary hardware serial ports without any problems whatsoever, so it would behoove you to use this more appropriate method instead. See reply #2. Please explain what problems you had with it. I've never noticed any difference at all between those and the default serial port.
As I suggested, the solution really is in the other topic. So closing it wasn't a great idea. But it can be continued here.