Except starting with Mac OS X Mavericks Apple is providing an O/S built in USB to serial driver. I am using the Apple provided USB to serial driver with CHIRP with zero problems.
Windows has provides an O/S built in USB serial driver. The dilemma is the stupid Microsoft thinks they should automatically provide the latest O/S built in USB serial driver. And that is absolutely the wrong thing to do if you are using a Prolific USB / serial cable.