This discussion was created from comments split from: One Step Update: Critical Malfunction.
I'm having the same problem. No transactions have downloaded since 6/14. I get the CC-601 error code and a statement that Quicken cannot find an account with a non-zero balance at AmEx. I did all the deactivate/add account steps with a real, live Quicken support person helping me. The only thing that happens is I get a single, large balance adjustment entry that seemingly adds all my charges since some unclear time (I certainly haven't incurred $4,186.93 in charges since 6/14). Ticket ID 12480486.
If you're a Q Windows user: First deactivate ALL AmEx accounts then, when all accounts have been deactivated, use Tools / Add Account to reactivate / reauthorize your accounts to Bank name American Express - Delegate.
This got me out of the CC-601 doghouse …
If you're a Q Mac user, try the same, if "American Express - Delegate" is available for you.