If the Quicken data file is damaged, you might receive prompts about downloaded transactions when you don't have any downloaded transactions.
If you know when this issue began, the best solution is to restore a backup created before this issue began.
If you do not have a backup to restore, Quicken has a built-in utility, Validate, that will correct any data issues. Please note this does not correct all issues and these steps should be taken if the other steps outlined did not resolve the problem.