TYPO3-Organiser: Ticketbestellung - Mwst. Sätze (wt_cart Error, undefined value..)

wt_cart Error
 
tax is "19.00".
This is an undefined value in class.tx_wtcart_pi1.php. ABORT!
Are you sure, that you included the wt_cart static template?

plugin.tx_wtcart_pi1.shipping {
  #set default shipping method
  preset = 1
  show_all_disabled = 1
  options {
    #shipping method 1
    1 {
      title = Standard
      extra = 5.00
      free_from = 50.00
      tax = normal
    }
    #shipping method 2
    2 {
      title = Express
      extra = 7.00
      tax = normal
    }
  }
}
 
plugin.tx_wtcart_pi1.payment {
  #set default payment method
  preset = 1
  show_all_disabled = 1
  options {
    #payment method 1
    1 {
      title = Cash on delivery
      extra = 2.00
      tax = normal
      )
    }
    #payment method 2
    2 {
      title = Cash in advance
      extra = 0.00
      available_until = 200.00
      tax = normal
      note (
        p><b>Please note:</b></p>
        <p>No money<br>
        No funny</p>
      )
    }
  }
}