I spent a long time reading through this forum and resetting everything only to find out the manufacturer installed the wrong program on my board. Admission of guilt found here ---- http://osepp.com/learning-centre/start-here/uno-r3-plus/
I don't know if it will help with authentic arduino boards (never had a problem with mine) but loading under the other board types worked for me. I just went down the list until I found the one that worked "Due 328" will load my sketches on my labeled UNO R3 board. Shame on you OSEPP. You get what you pay for!!!!