Take player ability to use command

Most of the time this isn't actually an issue with LuckPerms itself but here are a few troubleshooting tips:

• LuckPerms is not a chat formatter and another plugin is required to format the chat or tab list to include prefixes and suffixes.
  • If you are running a Bukkit based server (CraftBukkit, Spigot, Paper) then you also need to install Vault.
  • Some popular chat formatting plugins are listed here.
• Firstly, you should check if a prefix/suffix is actually set with LuckPerms - run /lp user <user> info and see if the prefix/suffix is displayed correctly. If so, great! LuckPerms has done its job and now it's up to your chat/tab/whatever formatter to display it correctly. If not, you need to set a prefix or suffix.
• If you are using Essentials, make sure you are running EssentialsX and EssentialsXChat. The X is important! Other versions of Essentials may not work correctly with LuckPerms.
  • Run /ess version for a quick rundown on your Essentials setup, this also reports whether Vault is installed and which permission plugin you are running - preferably LuckPerms! If the command only returns a message like "Reloaded Essentials [version]" then you are using an unsupported version of Essentials and should update to EssentialsX (linked above).
  • Essentials provides the {DISPLAYNAME} placeholder to its chat formats which will combine the prefix, nickname and suffix into one. If you do not like this behaviour then you can change the add-prefix-suffix option to false in the Essentials config.
• Are your prefixes/suffixes displaying, but not the right ones? You most likely need to set the priority/weight correctly. If you type /lp user <user> meta info and see a bunch of zeroes, or some/all of the numbers (priorities) are the same, LuckPerms will take the first highest one and use that as that user's prefix/suffix. To change these, you will need to set the prefix again using the correct command - or you can easily edit the number using the web editor. Prefixes and suffixes are stored as permissions, just like everything else, they look similar to this: prefix.100.[Admin] - the 100 there is the priority and this is the number you would change to edit it.
• Lastly, the meta-formatting section of the LuckPerms config is very important and you should make sure you only change it when necessary (e.g. prefix/suffix stacking). It's possible your prefixes/suffixes are not working because this section has been tampered with. If you want to set it back to default, make sure the format looks like this:

    format:      - "highest"