This article demonstrates how to load Arcade in Logic Pro X:
Open up your Logic project
Click the + icon above the track headers
Select Software Instrument as the track type
Click the instrument slot, then navigate down to AU Instruments > Output > Arcade
Click Create
Troubleshooting:
If you're unable to load Arcade in Logic Pro X the first step we recommend is restarting your computer.
If restarting your computer doesn't solve the issue, we recommend rescanning your plugins. To automatically rescan all installed plug-ins, please perform a Full Audio Unit Reset:
Choose Logic Pro > Preferences > Plug-In Manager.
Click Full Audio Unit Reset.
Close Logic Pro, then reopen it. Logic Pro rescans all installed Audio Units plug-ins.
Check Logic Pro or MainStage to see if the plug-in is available.
The above option is not available on older versions of Logic. If you do not have the option available in your plug-in manager, we can accomplish the same thing manually:
In the Finder, hold down Option and choose Go > Library in the top menu bar.
In the Finder window, go to Library/Caches/AudioUnitCache.
Move the files from AudioUnitCache folder to the Desktop.
Restart the computer, then open Logic Pro X. All of your installed Audio Units plug-ins will be rescanned.
To learn more about troubleshooting Logic Pro X, visit Apple’s support base.