Probably he is using MAC, it sometimes adds this weird symbol to the sign text.
That 3rd arg in manager.sendServerPacket was there not for no reason. It bypasses protocollib filters.
You didn't configured it, so ofc it does nothing. Your problem if that you don't cancel Pong packets, you do this only 1 time actually.
You can just keep sending server info messages, without sending pong message, and client will hold connection and display updated ping. Here is...
Just let bukkit die.
RIP bukkit :(
Set your JVM encoding to UTF-8.
Problem starts when somebody reloads the server and then go complain to some random plugin developer just because server crashed and there was a...
When you place blocks they trigger block physics update. So you should place blocks to chunk section via NMS, that should do the trick.
You replaced the plugin jar when it was running?
Bukkit.getOfflinePlayer is at your service.
Because client doesn't support custom inventories. So you should extend CraftInventory instead of impelementing inventory interface.
Write your own version of vault which know your plugin. Or use reflection tricks to make vault know your ecenomy. Or request your ecenomy plugin...
YOu should update plugins using an update folder, not replacing jars, it breaks java classloader. Also probably factions version which you...
Separate names with a comma.