Likewise, I've been trying to check-in online for an hour or so this morning without success.
The most common error message I got was "Service Unavailable - Zero size object - The server is temporarily unable to service your request. Please try again later."
I've just spoke to Qantas and was told the Online Check-in has been “switched off for the day” because of a problem reading the Online Check-in issued boarding passes at airports.
I was advised to keep trying through the day as it would be switched on again once the boarding pass reading problem was fixed.
The most common error message I got was "Service Unavailable - Zero size object - The server is temporarily unable to service your request. Please try again later."
I've just spoke to Qantas and was told the Online Check-in has been “switched off for the day” because of a problem reading the Online Check-in issued boarding passes at airports.
I was advised to keep trying through the day as it would be switched on again once the boarding pass reading problem was fixed.