[away3d] Problems importing to flash

[dapu17]

hi, i make a test of BSP exporter but when i try to do the steps that
are in the video i get the following error:
TypeError: Error #1009: No se puede acceder a una propiedad o a un
método de una referencia a un objeto nulo.
        at away3d.loaders::AWData/linkBSPNodes()
        at away3d.loaders::AWData/prepareData()
        at away3d.loaders::AbstractParser/parseGeometry()
        at away3d.loaders::Loader3D/loadTextures()
        at away3d.loaders::Loader3D$/parse()
        at away3d.loaders::AWData$/parse()
        at MyBSPProject/initAway3D()
        at MyBSPProject/init()
TypeError: Error #1009: No se puede acceder a una propiedad o a un
método de una referencia a un objeto nulo.
        at away3d.loaders::Loader3D/notifySuccess()
        at away3d.loaders::Loader3D/notifyMaterialLibrary()
        at away3d.loaders::Loader3D/onParserComplete()
        at flash.events::EventDispatcher/dispatchEventFunction()
        at flash.events::EventDispatcher/dispatchEvent()
        at away3d.loaders::AbstractParser/notifySuccess()
        at away3d.loaders::AbstractParser/parseNext()
        at away3d.loaders::AbstractParser/update()

what should i do....

thanks