When OLCI opened, I was successful in entering my KTN, sort of. I am travelling in a party of 4. When I went to OLCI, it asked me which passengers I wanted to check in. I selected all 4. It gave me the chance to enter in KTN for one passenger, and then my only other option was "continue". I hit continue, and before I knew it, I was checked in for all 4 passengers, with only 1 of 4 KTN entered. I called Emirates, and the agent I spoke with was super helpful. She didn't understand exactly how it worked, but "undid" my OLCI so I could try again. This time, I checked in one passenger at a time, and for each passenger I was given the chance to add KTN. I won't know if successful yet, as I was told I need to go to counter to pick up boarding passes. Will keep everyone posted, but secret seems to be to wait until OLCI opens, and then check in one passenger at a time. Good luck!