Error popped up last week when most of my accounts encountered CC-501 errors on an One Step Update. After multiple update attempts, validating my file, and rebooting my machine, there was no change in result, I reported the error and uploaded the requested files, but ultimately I resolved all of the errors by resetting the accounts. This appeared to work until the follow day when again using one step update, Quicken said it could not find one of my American Express accounts. I attempted to once again reset the accounts with the American Express website reflecting both accounts and requesting I check the accounts I wished to authorize as normal. However, Quicken still could only see one account on its side. I deactivated both accounts, super validated the file, shut down Quicken, and rebooted my machine and once again tried to add both accounts to no avail. Also tried different browsers just in case. Of note is although the accounts have different account numbers, they contain identical last four digits. As of now I cannot add nor download transactions for one of the cards. Looking for advice/assistance.