I seem to recall having that message before. What are you using to try and check in? Desktop or App? In the end, I was able to do OLCI, but in your situation, having a Y flex, maybe you're getting earmarked for an OpUp (but don't get your hopes up) and being Gold and Blue decreases chances of IDB.

Have you done any changes to the itinerary? Maybe a call to the call centre to check everything is okay with your tickets.

Hope everything is okay but please report back.

Safe & Happy Travels

S