Yahoo Astra flash component error BaseScrollPane not found

I'm trying to use the Astra library from Yahoo but I'm getting an error saying the base class BaseScrollPane is not found. It appears to be imported from fl.containers.BaseScrollPane, which leads me to believe it should be a part of the base flash 10 library and therefore should be available, but it appears to be missing. Is this part of a separate package from somewhere?

Update: For what it's worth, I found the actual class files in the Configuration/Component Source folder on my hard drive, but adding that to the class path (as well as the Components directory) did no good. I ended up fixing the issue by dragging a scroll pane compo开发者_开发百科nent to the stage from the Components window and then deleting it, but I'm not sure what exactly that action changed that made it work, and would like to know for future reference.

The "fl." packages are not part of the Flash Player.

So in order to use components that depend on them, you need to ensure that the required classes are compiled into your swf.

Dragging the ScrollPane worked because it brought along with it into your FLA's library the same classes that you needed.

If you're using one of the Astra components you'll need to drag it into your library (or on stage, and then delete it if you'd rather created it with ActionScript). The classes are pre-compiled into a symbol (just like the other fl.* components, like Button or List) and the skins are also symbols that must be in the library (unless you manually change all skin styles using the appropriate setStyle() calls).