With the release of the Professional edition of MyEclipse we've naturally begun issuing new professional subscription keys at purchase or renewal time. However, many of our customers would like to continue to run MyEclipse 3.8.4 / Eclipse 3.0.x installations and the new keys show up as an "expired license" since the 3.8.4 license manager does not understand the new key format.
To address this issue, we've released MyEclipse 3.8.5 as an update to 3.8.4. The only change is the licensing code, so the update is extremely fast and the risk of any problems is therefore minimal. If you have a MyEclipse 3.8.x installation that you'd like to upgrade to 3.8.5 you can do so by selecting "Help > Software Updates > Find and install... > Search for updates of the currently installed features > Finish".
Once Finish is selected, you should see a MyEclipse update for version 3.8.5. Once installed, please allow the workbench to restart as requested. Upon restart, your Professional key will be recognized appropriately.