Are you talking about a particular link within an exercise? Can you be more specific?
I believe what gshokie02 is referring to is the fact that the version 4.5 exercise files are recognized as previous version content once the 4.5.1 upgrade is installed. The program warns against using these files as they might cause corruption of the project (or possibly the software itself).
As Flash Builder evolves it would be logical for Flash Builder to not just notify of previous version content but offer a built in option to update not only the current project file, but perhaps also to be able to choose a folder and auto update/convert all files within as necessary.
I hope this helps clarify things.
Exactly what I'm talking about. NetBeans, for example, offers this functionality with its upgrades -- when you open a 6.8 project in 6.9 it prompts you that it will upgrade it to the new format and you may or may not be able to open it in the older version (depending on the changes). Having to export from the old version, then re-import to the new version seems like a lot of effort that I should only have to take if I decline the automatic upgrade.