Not really new topic but have spent hours trying to get answer

I just received my arduino uno kit from Mactrast with a complete course. The instruction booklet that came with it is from seeed studio. I am trying to install on my Macbook Pro OS 10.10.5 I have followed the instructions numerous times using the instructions in the course sponsored by UDEMY. Every time I try to download the blink program I get the following error message which means nothing to me. It refers me to the forum and I go in circles. Arduino: 1.7.8 (Mac OS X), Board: "Arduino Uno"

Arduino: 1.7.8 (Mac OS X), Board: "Arduino Uno"

Arduino: 1.7.8 (Mac OS X), Board: "Arduino Uno"

Sketch uses 1,030 bytes (3%) of program storage space. Maximum is 32,256 bytes. Global variables use 9 bytes (0%) of dynamic memory, leaving 2,039 bytes for local variables. Maximum is 2,048 bytes. avrdude: ser_open(): can't open device "/dev/tty.GoddesssiMac-SerialPort": Resource busy ioctl("TIOCMGET"): Inappropriate ioctl for device Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

I am obviously choosing something wrong but I have no idea what any of this means. Very frustrated!

Your IDE is from a different company. http://www.arduino.org/software You need to ask them.

Here's the background on this. http://forum.arduino.cc/index.php?topic=358657.0

Or download and install an IDE from arduino.cc ;)