Your rider item list contains all items that artists have ever requested at your events. It's entirely possible to have doubles end up in there, due to someone making a spelling mistake or USING CAPITALS.
If you want to clean up your list you can follow these steps:
- Head on over to your Launchpad
- Click Settings > Program > Rider items
- Look carefully through your list. See something that doesn't need to be there?
- Click the garbage icon behind it
And that's it!
Be careful not to delete any items that are currently being used in your events.