Trying to check-in for a flight from Europe to Qatar. It's now 40 hours to departure, and I keep getting a message that flight is not open for checkin, and the check in will open 48 hours before departure.

This is not a flight from/to the US, which I know has different deadlines, so I'm wondering when online check-in does actually open, as the claim of 48 hours before is evidently not true.