You appear to e trying to use Moneydance's embedded browser to download transaction data.
This browser is what is started if you have configured a web address in the account info screen and then click on the Download button in the register.
This feature is still very much in development and there are many banks worldwide it does not work with.
You have two basic choices.
1. Use your system browser to connect to your bank You can start this in Moneydance in two ways.
~ Use the Open Account website tool by taking the menu option Online --> Open Account website.
~ Hold down the Ctrl key(Command key on a Mac) when clicking on the download button will also open up your system browser.
2. Use Direct Connect to set up an automatic download connection from your bank, see: