If you’re using an older version of After Effects, such as CS6, you may see an error message when you apply the Prolost After Effects presets. This “missing effect” error does not harm your ability to use the presets. Just press OK to bypass the message, and use the presets normally. They’ll display in the Effects Control Pane as “Missing,” but there’s nothing wrong, and the presets will work perfectly.
You’ll also see the missing effect error when you re-open a project that uses the presets. The error is annoying, but harmless. Adobe has fixed this issue in recent versions of After Effects CC.