NC's September test instructions tell Steam players to remove the Playtest app and download Aion 2 separately. PURPLE users were told no additional step was needed. Those instructions concern the launcher, not a new character progression rule.
Check the library entry first
Before diagnosing a failed launch, read the name of the application you are opening. Keep enough disk space for the release client and use the official store or launcher to obtain it. An old desktop shortcut is convenient, but it is not proof that the correct application is installed.
Do not turn a download into an account problem
Our suggestion is simple: confirm the client, account and region before changing anything else. Do not create a second account just because a test shortcut no longer works, and do not use third-party downloads promising a faster install. If a later official notice changes the process, follow that notice. This is a preparation checklist, not confirmation that pre-download is already open at the time you read it.