Make sure that:
Setting up chests is necessary for your game to be playable. By default, the chests are empty, which means that there won't be any items in the chests when the game starts.
To fix this, you will need to create your own chest loot. You can simply do this ingame without editing any files.
Add items to your chests using the command /sw chestadd [type] [method] [percentage]. In this command, the [type] variable can be either
basic, basiccenter, normal, normalcenter, op or opcenter. This is the chest type that should receive the items.
Second, there is the [method] variable. This can be either HAND or INV. Use 'hand' to just add the item that is in your main hand, and use 'inv' to add all inventory items at once.
And third, there is the [percentage] variable. Most people do not understand it, but it isn't that complicated. This is just an integer between 1-100 that represents the rarity of the item for the chests. Meaning that when the percentage is 100, the item will be in all chests, and when the percentage is 1, there is only 1% for the item to be in the chest.
Example: /sw chestadd normal hand 50.
This will add your hand item to the NORMAL chest with a rarity of 50%.