CratesPlus Reloaded is provided as is without any guaranteed support. Posting in the discussion tab may get you help from other user's on Spigot. I Will try to answer any and all questions or concerns you have.
Note: The original plugin can be found here and supports older versions of minecraft. https://www.spigotmc.org/resources/cratesplus-free-crates-plugin-1-8-1-16-4.5018/

• Custom Crates!
• In-game editing!
• Knockback if a player opens crate without a key
• Keys can not be placed
• GUI when winning
• Easy to use and setup, even for voting systems!
• Holographic titles above crates, using Holographic Displays.
• Dependency on Protocol Lib

Openers - Customize how crates open! See a list of known openers here.

A full example config with notes can be found here to help you out with configuring the plugin, includes examples of perms, percentages/chances, commands, blocks and more: http://pastebin.com/grPRrSXp

It's advised not to use the in-game GUI if you edit the configuration file. As data will be lost due to the in-game GUI not supporting the same range of features as the config does. There is also a Wiki over on GitHub that has some documentation on the plugin.

• /crate settings - Allows you to edit crate winnings in-game
• /crate reload - Reloads CratesPlus config
• /crate create <name> - Create a new crate
• /crate rename <old> <new> - Rename a crate
• /crate delete <name> - Delete a crate
• /crate crate <type> [player] - Get a crate to be placed, place this in a protected area such as the server spawn.
• /crate key [type] <player/all> [amount]- Give the player (or all players) a crate key which can they be opened. Useful for shops and voting systems.
• /crate command (name) (command without a "/"). - Create a command item
  
• /minecraft:kill @e[type=armor_stand,distance=..2] - Removes holograms of deleted crates

• cratesplus.admin - Access to all /crate commands. Defaults to OP.
• cratesplus.updates - Any player with this permission will be notified of updates. Defaults to OP.

CratesPlus has always been my go to crates plugin of choice. With the ease of use and user friendliness. That is why I have decided to update this plugin.