Problems with Sthrattoff Quest log script

[destiny]

hi 
i need some help with this script because im getting an error 
the error:

Script 'Window_Command' line 18: RGSSError occurred.
failed to create bitmap

Line 18 in Window_Command:

Code Select Expand


self.contents = Bitmap.new(width - 32, @item_max * 32)


please help me =)
Thanks in advance!