Re-install the Webstart (Download Edition) of Athena Player
In the event that the application won't start all of a sudden, it may be necessary to re-install it, as a first attempt to resolve the issue though, its worth rebooting your machine and trying to run it again. If the problem persists, follow the instructions below to re-install the product.
The re-installation process involves deleting the cached version (instructions here), then using the instructions sent to you when you first installed the application to re-install it. Your serial will work fine when you re-install.