Update 2/19/19: Now possible to transfer again.
Currently it’s not possible to transfer American Express Member Rewards Points to Avianca LifeMiles, when clicking through the transfer page it says they are unavailable due to system migration and no date is given for when these transfers will be available again. From February 1st until February 5th the LifeMiles system was unavailable, so I suspect this is part of that. Yesterday they launched the new LifeMiles site, although there are still a lot of bugs and issues there.
Hat tip to TPG
