Easy Custom Labelling Error Code

Question

I'm getting the following error - only on one of the vectory layers in my project. Can anyone help? Have tried a restart and reloading the layer and neither worked!

An error has occured while executing Python code:


Traceback (most recent call last):
  File "C:/Users/Claire/.qgis2/python/plugins\EasyCustomLabeling\EasyCustomLabeling.py", line 506, in runLabel
    WKTLine = 'LINESTRING('+ str(geom.centroid().asPoint().x() +0.0001) +' '+  str(geom.centroid().asPoint().y() +0.0001 ) + ' , '+ str(geom.centroid().asPoint().x())+ ' ' +str(geom.centroid().asPoint().y())+ ')'
AttributeError: 'NoneType' object has no attribute 'asPoint'


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


QGIS version:
2.10.1-Pisa Pisa, d20c5b7

Python path: ['C:/PROGRA~1/QGISPI~1/apps/qgis/./python/plugins\\processing', 'C:/PROGRA~1/QGISPI~1/apps/qgis/./python', u'C:/Users/Claire/.qgis2/python', u'C:/Users/Claire/.qgis2/python/plugins', 'C:/PROGRA~1/QGISPI~1/apps/qgis/./python/plugins', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\matplotlib-1.3.1-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\nose-1.3.3-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\tornado-4.0.1-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\backports.ssl_match_hostname-3.4.0.2-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\certifi-14.05.14-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\bin\\python27.zip', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\DLLs', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\plat-win', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\lib-tk', 'C:\\PROGRA~1\\QGISPI~1\\bin', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\PIL', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\jinja2-2.7.2-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\markupsafe-0.23-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\pytz-2012j-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\win32', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\win32\\lib', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\Pythonwin', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\Shapely-1.2.18-py2.7-win-amd64.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\six-1.3.0-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\wx-2.8-msw-unicode', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\xlrd-0.9.2-py2.7.egg', 'C:\\PROGRA~1\\QGISPI~1\\apps\\Python27\\lib\\site-packages\\xlwt-0.7.5-py2.7.egg', u'C:/Users/Claire/.qgis2//python', 'C:\\PROGRA~1\\QGISPI~1\\apps\\qgis\\python\\plugins\\fTools\\tools', 'L:/AC/00018A Northampton Cathedral/GIS']

Answer 1

The Easy Custom Labeling plugin works fine for other layers which have empty attributes, so that is not the issue.

I ran a 'Check Geometry Validity': this came up with nothing.

I then created an 'Area' attribute and populated this, which flagged up that one of the polygons had no area, and therefore no geometry. I deleted this polygon and now it works fine.

So the issue does seem to be NULL geometries. There's probably a quicker way to identify them though.