Originally Posted by
bocastephen
Perhaps I'm just not remembering something - but is upgrade seat availability tied to the fare bucket you choose, or do certain fares (Y, B, M) pull from a different pool?
No and no. I'm guessing it is a co.com bug where it is still looking at Y/B/M upgrades as booking into CU/AN/AN rather than the actual booking class that those upgrades go in to. Did you try going all the way through to actually process the upgrade?