An error has occured while executing Python code:

Traceback (most recent call last):
  File "C:\Users\JOAO/.qgis2/python/plugins\processing\modeler\ModelerDialog.py", line 324, in addAlgorithm
    self.repaintModel()
  File "C:\Users\JOAO/.qgis2/python/plugins\processing\modeler\ModelerDialog.py", line 281, in repaintModel
    self.scene.paintModel(self.alg)
  File "C:\Users\JOAO/.qgis2/python/plugins\processing\modeler\ModelerScene.py", line 146, in paintModel
    ParameterMultipleInput))
  File "C:\Users\JOAO/.qgis2/python/plugins\processing\modeler\ModelerScene.py", line 87, in getItemsFromAAP
    aap = AlgorithmAndParameter(float(token.split('|')[0]),
ValueError: could not convert string to float: 

Python version:
2.7.4 (default, Apr  6 2013, 19:54:46) [MSC v.1500 32 bit (Intel)]


QGIS version:
2.0.1-Dufour Dufour, ebebdf3

Python path: ['C:\\Users\\JOAO/.qgis2/python/plugins\\processing', 'C:\\Users\\JOAO/.qgis2/python/plugins\\LecoS', 'C:/OSGeo4W/apps/qgis/./python', 'C:\\Users\\JOAO/.qgis2/python', 'C:\\Users\\JOAO/.qgis2/python/plugins', 'C:/OSGeo4W/apps/qgis/./python/plugins', 'C:\\OSGeo4W\\bin\\python27.zip', 'C:\\OSGeo4W\\apps\\Python27\\DLLs', 'C:\\OSGeo4W\\apps\\Python27\\lib', 'C:\\OSGeo4W\\apps\\Python27\\lib\\plat-win', 'C:\\OSGeo4W\\apps\\Python27\\lib\\lib-tk', 'C:\\OSGeo4W\\bin', 'C:\\OSGeo4W\\apps\\Python27', 'C:\\OSGeo4W\\apps\\Python27\\lib\\site-packages', 'C:\\OSGeo4W\\apps\\Python27\\lib\\site-packages\\PIL', 'C:\\OSGeo4W\\apps\\Python27\\lib\\site-packages\\win32', 'C:\\OSGeo4W\\apps\\Python27\\lib\\site-packages\\win32\\lib', 'C:\\OSGeo4W\\apps\\Python27\\lib\\site-packages\\Pythonwin', 'C:\\OSGeo4W\\apps\\Python27\\lib\\site-packages\\Shapely-1.2.18-py2.7-win32.egg', 'C:\\OSGeo4W\\apps\\Python27\\lib\\site-packages\\wx-2.8-msw-unicode', 'C:\\OSGeo4W\\apps\\qgis\\python\\plugins\\fTools\\tools']