Niezrozumiały błąd

[16:51:31] [Server thread/ERROR]: a slot can't be set to 'glass nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 336: set slot 0 of {_gui} to glass nammed "."')
[16:51:31] [Server thread/ERROR]: a slot can't be set to 'diamond sword nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 337: set slot 1 of {_gui} to diamond sword nammed "."')
[16:51:31] [Server thread/ERROR]: a slot can't be set to 'glass nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 338: set slot 2 of {_gui} to glass nammed "."')
[16:51:31] [Server thread/ERROR]: a slot can't be set to 'glass nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 339: set slot 3 of {_gui} to glass nammed "."')
[16:51:31] [Server thread/ERROR]: a slot can't be set to 'glass nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 340: set slot 4 of {_gui} to glass nammed "."')
[16:51:31] [Server thread/ERROR]: a slot can't be set to 'glass nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 341: set slot 5 of {_gui} to glass nammed "."')
[16:51:31] [Server thread/ERROR]: a slot can't be set to 'glass nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 342: set slot 6 of {_gui} to glass nammed "."')
[16:51:31] [Server thread/ERROR]: a slot can't be set to 'glass nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 343: set slot 7 of {_gui} to glass nammed "."')
[16:51:31] [Server thread/ERROR]: a slot can't be set to 'glass nammed "."' because the latter is neither an item type nor an item stack (bedwars.sk, line 344: set slot 8 of {_gui} to glass nammed "."')

function shop(p:player): 
    set {_gui} to a new chest inventory with 6 row with name "Sklep"
    set slot 0 of {_gui} to glass nammed "."
    set slot 1 of {_gui} to diamond sword nammed "."
    set slot 2 of {_gui} to glass nammed "."
    set slot 3 of {_gui} to glass nammed "."
    set slot 4 of {_gui} to glass nammed "."
    set slot 5 of {_gui} to glass nammed "."
    set slot 6 of {_gui} to glass nammed "."
    set slot 7 of {_gui} to glass nammed "."
    set slot 8 of {_gui} to glass nammed "."
    open {_gui} to {_p}