This error is caused by an incorrect security setting on your computer. In order to function, Blackboard needs to be able to execute scripts on your computer. To activate scripts in Internet Explorer, go to the Tools menu -> select Internet Options -> and click on the Security Tab. Now, click on the "Internet" zone icon (the globe) at the top of the screen. Next, click on the Custom Level button at the bottom of the screen. Scroll down the page until you find the Scripting section and be sure Active Scripting is enabled. Blackboard requires scripting to be turned on in order to work correctly, however if you are concerned about this setting you can change it back to the previous setting when you finish using Blackboard.
Try out the Browser Check tool on the Help tab to see if anything else is wrong.