There is a known problem in the OS X version of Metro 6.0 regarding the Plug In Effects Processor. Please visit the downloads page for a free upgrade to 6.0.1 or later.
Adding effects offline preserves your computer’s processing capacity. To keep your original audio data intact and readily
accessible, it’s a good idea to copy your audio track and apply effects to the copy.
To apply effects offline:
Select a track or region in a track to add an effect to.
From the Edit menu, choose Audio and select an effect from the submenu.
The Plug In Effects Processor dialog box appears.
Click the Preview button to hear a preview of your track with the selected
effect.
If you like the effect, click OK. Otherwise, click Cancel and select another
effect.
There is a