Many financial institutions will require you to enable your accounts for application-based online banking. You can accomplish this by asking your bank to set up your account for direct connections from Quicken. Moneydance uses exactly the same OFX server connection protocol as Quicken but your bank representative may not know this and mistakenly believe that you can not connect in Moneydance. Calling up your bank and stating precisely the following should get you started. "Please enable direct connect on my account such that I can connect to your servers directly with Quicken. Also give me the login credentials I need to connect Quicken to this service."
Application-based online banking often requires a different login/PIN than the ones that are used for ATM or web-based banking. When you enable your account for access from Moneydance or Quicken, your financial institution should let you know what customer ID/login and PIN to use.
Many banks charge a monthly fee for direct connections, please refer to your bank for more information.