Internal Server Error when buying items with lore

[vLilly]

11:11:34] [Server thread/WARNING]: Key 'purchase-item' could not be found in the 'de_DE' language file, add this key to the language file or update the file by deleting it and restarting the server.
[11:11:34] [Server thread/CRITICAL]: ErrorException: "Illegal string offset 'lore'" (EXCEPTION) in "plugins/AuctionHouse/src/shock95x/auctionhouse/menu/ConfirmPurchaseMenu" at line 39
[11:11:34] [Server thread/CRITICAL]: #0 plugins/AuctionHouse/src/shock95x/auctionhouse/menu/ConfirmPurchaseMenu(39): pocketmine\utils\Utils::errorExceptionHandler(integer 2, string[28] Illegal string offset 'lore', string[91] /home/container/plugins/AuctionHouse/src/shock95x/auctionhouse/menu/ConfirmPurch, integer 39, array[3])
[11:11:34] [Server thread/CRITICAL]: #1 plugins/AuctionHouse/src/shock95x/auctionhouse/menu/AHMenu(66): shock95x\auctionhouse\menu\ConfirmPurchaseMenu->renderItems()
[11:11:34] [Server thread/CRITICAL]: #2 plugins/AuctionHouse/src/shock95x/auctionhouse/menu/ConfirmPurchaseMenu(31): shock95x\auctionhouse\menu\AHMenu->construct(object core\CrypticPlayer)
[11:11:34] [Server thread/CRITICAL]: #3 plugins/AuctionHouse/src/shock95x/auctionhouse/menu/AHMenu(147): shock95x\auctionhouse\menu\ConfirmPurchaseMenu->construct(object core\CrypticPlayer, object shock95x\auctionhouse\auction\Listing)