If you want the official Adobe solution, follow these steps to unhide the effect:
The "Lens Blur" effect was officially removed from After Effects in version CS5.5 and replaced by the modern effect. If you see a "Missing Effect" error, it is likely because an older project file was opened in a newer version of the software where the legacy plugin no longer exists . Why "Lens Blur" is Missing lens blur after effects missing free
You check the effects menu again. Nothing. You restart the software. Still nothing. If you want the official Adobe solution, follow
Right-click After Effects > "Run as Administrator." This grants permission for plugins to register in the effects menu. lens blur after effects missing free