Voidchest will not attempt to convert old data to the new data saving system. In order to update the plugin do the following:

• Make sure your server is stopped.
• Save all your voidchest files
• Delete the voidchest plugin folder.
• Replace the old voidchest jar with the new one.
• Start your server.
• Having all new files loaded, apply the appropriate changes.
• Use the reload command or restart your server to make sure everything loads properly.

• [ ~ ] 1.14 - 1.14.4 is now fully supported. There was an issue with NBT Tags earlier due to 1.14 being a relative new version. The plugin has been thoroughly tested and should function properly in any 1.14x version.
• [ ! ] Changed the give command to : /vc give ...
  • Example: /vc give normal Shin1gamiX 1
  • Example: /vc give normal Shin1gamiX
    
  • Example: /vc give normal
• [ ~ ] Fixed a bug with the list command. For example, if you were to have 2 voidchests (Normal and Vip), and then tried to give a player a voidchest with the name normal, it would bug and show 3 available voidchests (Normal, normal, Vip). And this would go on for as long as you typed out the same voidchest with different caps.
• [ ~ ] Fixed a bug with the shopguiplus mode not selling certain items.
• [ ~ ] Hopefully fixed a bug with players changing their names and have their voidchests not function anymore.
• [ + ] Added a new feature named charge. This feature acts as fuel for any voidchest that you configure to have it. Players will need to pay in game money in order to give "fuel" so as to allow the voidchest to function properly. An estimated time of the voidchest's working time can be displayed in the hologram if available or the voidchest menu inventory.
• [ + ] Added an option to delay voidchest's data load when the plugin enables. This will hopefully fix issues with worlds not being loaded in time and voidchest fails to load data related to these worlds.
• [ + ] Added an option to delay voidchest's hook with a different economy plugin (essentials, shopguiplus or voidchest's own logic). This delay is the same as the above.
• [ + ] Added an option to prevent voidchests from being placed next to each other (this can be toggled on and off for each individual voidchest on their own file).
• [ - ] The saving task has been removed completely.
• [ + ] Added an option in the options.yml file so as to toggle on and off whether you want voidchests to function in case their owner is offline.
• [ + ] Added some debugging shown only to me when I join a server using my plugin, this debugging shows stats such as what mode the plugin is using, some information about it, how many voidchests there are on the server, which version the plugin is, etc.
• [ + ] Added an option to disable the voidchest menu inventory. If this is disabled, performance in general should be enhanced greatly since the plugin wouldn't be required to deal with inventories whatsoever.
• [ + ] You can know translate the time in voidchest's hologram countdown feature through the options.yml file.
• [ + ] Greatly enhanced inventory handling, this should optimize performance by a whole lot.
  
• [ + ] Hologram updating task optimized.
• [ + ] Voidchest place limit has changed and you can now allow
  
• [ ! ] Data will no longer be stored in a single file. Each player will get their own unique file located in a folder named "PlayerData".
• [ ! ] The plugin will no longer save data on a player's name. UUID will be used instead so as to prevent issues with name changing in online-mode servers.players to have different limits depending on their permission. More information can be found in the options.yml file.
• [ ! ] The sell interval in the options.yml file has changed to ticks from seconds.
• [ ! ] The voidchest-inventory file has been removed and from now, each voidchest will have it's own individual file located in a folder named "VoidChests", inside voidchest's main folder.
• [ ! ] The messages section from the options.yml file have been removed and have been transfered to each voidchest's file.

This list is so huge, I may have even forgotten some other changes made but these should be the main ones.