Originally Posted by DragonSoul

Used the Klook paper print-out for check-in at the Airport Express in the morning and tried to use the QR code on my phone for the train later. Unfortunately (and I didn't notice), at the station my phone flipped from 4G to the station wifi and the email wouldn't open. As it wouldn't open and I couldn't find the darn paper code in my bag (found it later of course), I missed the train. Sorted out the phone and used it to get through on the QR code reader.

Next time I'll screenshot the QR code (or perhaps just keep the print-out handy). Duh!