"YOUR ITINERARY HAS MIXED CABINS" warning with single flight
 

I've currently booked a one-way ANA award with my Aeroplan miles, from the O bucket, which I believe is first class. There's only one flight in the reservation, so I'm not sure why the mixed cabin warning is appearing. Nothing turned up when I searched.

Does anyone know what could be going on?

Could be a F award booking (booking class "O") with the aircraft only having a business class cabin (booking class "I"). What's the route, flight number and (approx.) date if I may ask?

A few questions since you post did not provide this info:

Was it your intention to book First?
Does the flight have a F class?
Do you have the ANA Booking Reference and e-ticket number?
If yes, you can check it on ANA's site (where you can also select your seat)

Yes to all of your questions. I have selected a first class seat.

[Redacted] As far as I can tell, it will still be the 77W. Additionally, I was able to select my seat.

I don't want to lull you into a false sense of security, but you're talking about Aeroplan here.

I'm pretty sure even I have posted messaged about mixed cabins in the "Aeroplan.com sucks" thread.

If NH says you're good, then you're good.

Yes, I think someone posted this same problem a few days ago with a one-way, single-flight itinerary, although I couldn't find the post.

Thanks canadiancowand Adam Smith. I wasn't able to find anything in the aeroplan.com thread or another thread, but I'm happy that it's my search skills and not reservation that's faulty.