CCleaner wrongly identifies (I still don't know why) this registry key:
as belonging to "Oxygen XML Editor 14"
Actually this "false positive" makes reference to any of this three programs:
which are manufactured by ej-technologies GmbH
install4j and exe4j are known softwares for managing installation and uninstallation of popular Java-based software such as DbVisualizer Free and JDownloader.
In the tests I did in my computer, I realized that it is not necessary to complete the installation of software which uses this installer technology: by only starting the installation creates the troublesome registry key.
I also found that upon uninstalling software which uses this technology it is also created the troublesome registry key and it remains even after successfully completing the uninstallation process.
If none of ej-technologies programs (JProfiler, install4j, exe4j) is installed in your computer, and no Java-based software using this kind of installer is installed in your computer, it is safe to delete this registry key, although in any case it is recommended to always make previously a registry backup.
Next time you start CCleaner, you will see how "Oxygen XML Editor 14" application entry will have disappeared from the Applications list.