I flew out of Shanghai a few days ago. At 24 hours before departure, I received an email that I could OLCI. I went through the process but near the last step, it reported an error that I needed to see a desk agent. I was on Chrome, and then tried another browser (Edge) with the same result. I remembered in the past that there were issues with the check-in agent needing to see the passport information, but also remembered that I had been able to check in without that (I am Canadian flying back to Canada so there should not have been visa issues). So when section came up about passenger information, I clicked on edit, didn't change anything, and then saved it. Then it worked, and I got my boarding pass for PVG-YVR, and also that for the connecting flight 1.5 hours later for YVR-YYZ (which I missed but that's another story). I didn't print out a paper copy since I didn't have access to a printer at that time, but I got the electronic version on the app on my phone. At PVG where I arrived 10 hours early because my 4-hours-early flight had been cancelled, I went to the check-in area for AirCanada not expecting anyone to be there, but expecting there to be machines to print out boarding pass. There weren't any machines for AirCanada (although there were ones for other airlines which didn't have access to AirCanada flights). At the information desk near the AirCanada check-in area (section G), I asked about using my cell phone boarding pass to enter security. I had seen people use their cells phone at PVG domestic which is screened by an agent just before the luggage screening area, and they usually put a red stamp on the paper boarding passes. For the cell phones, they passed them a slip of paper when the phone was returned which I assume is equivalent to the stamp. They asked me which airlines the cell phone boarding pass was for, and when I said AirCanada, they said that security would not accept it, and that I needed a paper version. They just pointed to the side and said I could go there when it opened at 1:30pm (which was 2 hours later). I walked around and chilled out with McD ice cream directly one floor down with uncrowded seating areas (including benches where you can lie flat - I had already been travelling since 5am that morning and was dreading the 10.5 hours on the plane to YVR since my Eup request wasn't going to work because all seats in J and PE were taken). After getting my boarding passes, went through security and went to the AirChina lounge. Even though it was still almost 5 hours before the flight, there was no problem getting in (no 3 hr limit as with MLLs).