Hack to reauthorize American Express on Quicken Classic Windows
I started having problems when I changed the email associated with my Quicken file. All of my connections were broken, but most of the accounts would reconnect when I activated online setup — all except American Express.
So I deactivated all of my AE accounts and removed the Account Number from the Account Details - General window. Then I logged in to americanexpress.com, downloaded tx to Quicken for an account, and opened that .ofx file; for some files, Quicken recognized it as having "compatible" info and would load the tx, but other files, it would fail. As long as you get one account that Quicken will load the tx from the .ofx file, you should be fine, as it will establish a connection to AE. Then I opened the Account Details - Online Services window and clicked the link to use the better connection method. Quicken then began the reauthorization process and I was able to reconnect all of my AE accounts.