This version of AirPort Utility doesn’t support this base station. Solved

Do you still have an older Apple WiFi router? Do you still need to configure it?

Take a look at your AirPort Express and locate the model number in the faint print. Do you you have an A1084 or A1088 model? Unfortunately, these older versions of the Express are no longer supported by the newer operating systems (Mac OS X Lion, Mountain Lion, Mavericks or Sierra). Read More