Quicken Community is moving to Single Sign On! Starting 1/22/21, you'll sign in to the community with your Quicken ID. For more information: http://bit.ly/CommunitySSO
Warn for Duplicate Check Numbers
There doesn't seem to be any kind of warning for duplicate check numbers either when entering transactions manually, or downloading from my bank -- I just ran into an issue where a check was processed twice (yikes), and didn't realize it (they were on two separate statements) until the bank caught the error and redeposited the funds. A duplicate number warning would have helped me catch the error immediately.