My plugin is making LuckPerms produce an NPE. All it says is "permission". I have debugged and confirmed that the permission is not null.
The permission nodes are:
rankgrantplus.grant
custom.permission

Could it be possible that custom.permission might produce an NPE because it doesn't start with the plugin name?

What's the full stack trace?

https://pastebin.com/DqyuevzF

RankGrant+ is at https://github.com/Demeng7215/RankGrantPlus
Line 51 is if (op.hasPermission(i.getRanks().getString(path + "permission"))) {, keeping in mind that I have debugged and that line is not null.