Inventory

When you perform the Network Components setup on the First-Person Controller, the Inventory system is automatically networked by default. However, it still requires one additional step for proper configuration.

Remember: You can network the Inventory system independently by following the same process Setup > Network Components.

The Inventory can pickup and drop network objects, however it doesn't have a way of letting other clinets know just yet. To fix this, assgin all the items you have in your project in Items list of NetworkInventory:

Make sure that those items you assgin are network properly as shown in Firearm page.