Thanks for this plugin,But I find a error,when I add the plugin,players can't see others.My game is 1.12.2 spongeforge,Wish you updata the plugin and solve the problem

This is nothing that LP manages.
The only reason this happens is of how Spongeforge manages OP and permissions.
As soon as a permission plugin is installed are all OPs disabled (for obvious reasons.)

What I want to say is, that this is not an error by LuckPerms (since LPs code has nothing that manipulates players) but rather missing permission from another plugin.
Check your plugins for any kind of vanish command/permission.

oh! this plugin is no problem if add it only,but I add the Nucleus,It's going to happen as before I said.

Don’t give the permission *, nucleus or nucleus.*. Because that’ll include a permission that will make you join vanished.