Arduino will not recognise USB ports on my Mac running Sierra I am a teacher who helps teachers to use LilyPad. I used to be able to plug in my LilyPad Arduino and see the USB port. I have read all the answers and dowloaded the drivers from Spark fun and another driver from Github. Nothing is working and i am not technical enough to find the answer myself. I have spent three hours today trawling through the answers to this problem and still cannot fix it myself. I am a luddite who needs a simple step by step remedy. Apple support had no idea when I rang them and told me it was an Arduino problem and to talk to them. you cant talk to anyone at Arduino you can only go to the forums. the forums tell you to read others answers before you post. I have. it's still not working. i need help. And not a lecture about being on a forum asking dumb questions.
I even mucked around in terminal and am hoping it's not a 'terminal" problem because I have no clue what i am doing. If you can explain in plain speak please respond. i have to teach this stuff in 4 days.
This is the message I get when I try to upload a sketch