Why does the Contour Plugin failt to load in QGIS Valmiera?

Question

Whenever i try to load the contour plugin. I get the error as follows: The same happens to when i try to load Qgis2leaf plugin...

An error has occured while executing Python code:

Traceback (most recent call last):
  File "C:/Users/Lenovo/.qgis2/python/plugins\contour\contour.py", line 112, in run
    dlg = ContourDialog(self._iface)
  File "C:/Users/Lenovo/.qgis2/python/plugins\contour\contour.py", line 151, in __init__
    self.setupUi(self)
  File "C:/Users/Lenovo/.qgis2/python/plugins\contour\frmContour.py", line 80, in setupUi
    self.uDataField = gui.QgsFieldExpressionWidget(self.groupBox_2)
AttributeError: 'module' object has no attribute 'QgsFieldExpressionWidget'

Python version:
2.7.5 (default, May 15 2013, 22:44:16) [MSC v.1500 64 bit (AMD64)]


QGIS version:
2.2.0-Valmiera Valmiera, c3a2817

Python path: ['C:/PROGRA~1/QGISVA~1/apps/qgis/./python/plugins\\processing', 'C:/PROGRA~1/QGISVA~1/apps/qgis/./python', u'C:/Users/Lenovo/.qgis2/python', u'C:/Users/Lenovo/.qgis2/python/plugins', 'C:/PROGRA~1/QGISVA~1/apps/qgis/./python/plugins', 'C:\\PROGRA~1\\QGISVA~1\\bin\\python27.zip', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\DLLs', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\plat-win', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\lib-tk', 'C:\\PROGRA~1\\QGISVA~1\\bin', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\PIL', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\win32', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\win32\\lib', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\Pythonwin', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\Shapely-1.2.18-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\six-1.3.0-py2.7.egg', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\wx-2.8-msw-unicode', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\xlrd-0.9.2-py2.7.egg', 'C:\\PROGRA~1\\QGISVA~1\\apps\\Python27\\lib\\site-packages\\xlwt-0.7.5-py2.7.egg', 'C:\\Users\\Lenovo\\.qgis2\\python\\plugins\\mmqgis/forms', 'C:\\PROGRA~1\\QGISVA~1\\apps\\qgis\\python\\plugins\\fTools\\tools', 'D:/Works at ICIMOD/QGIS Tutorials']

Answer 1

The Contour plugin metadata seems incorrect concerning the minimum QGIS version required.

The earliest version including QgsFieldExpressionWidget is 2.4 http://qgis.org/api/2.4/annotated.html