Removing Robot IR Arduino Library on Macbook
The folder name is RobotIRremote.

It's actually not necessary to remove that folder, though that will solve your problem. A better solution is to change the folder name of the IRremote remote library so that the file named IRremote.h found in that library will be given include priority over the one found in the RobotIRremote library. This is better because you would need to remove the RobotIRremote library every time you update to a new version of the Arduino IDE. The Arduino IDE gives include priority to files that match the name of the library folder but unfortunately if you install the IRremote library manually it will tend to have the folder name Arduino-IRremote-master which causes the wrong file to have priority. So you just need to find that folder and rename it IRremote.

If you don't know where it is the library folder can be found by:


File > Examples > IRremote > AiwaRCT501SendDemo
Sketch > Show Sketch
Folder