Plugin doesn't work :/

[CrackerFR]

After i have put the plugin on my server, if a player join the server, i have this error on the console :
Notice: Undefined index: in /home/eradiape/eradia_server/src/pocketmine/inventory/PlayerInventory.php on line 92
Notice: Undefined property: PocketEssential\BossBarAPI\UpdateAttributesPacket::$selectedSlot in /home/eradiape/eradia_server/src/pocketmine/Player.php on line 2391
Notice: Undefined property: PocketEssential\BossBarAPI\UpdateAttributesPacket::$slot in /home/eradiape/eradia_server/src/pocketmine/Player.php on line 2391

And the player don't have the BossBar :/

Wish software ?