I have to add more than 20 fields to a lot of shapefiles using QGIS 2.4. I used to do it with the tablemanager plugin. Beside it is time consuming, misstakes can be made. So I want to automate that procedure through the graphical modeler.

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I tested it with adding 2 fields and everything worked fine. But when I added all the algorithms it gave an error:

Error executing algorithm 2 [Errno 9] Bad file descriptor See log for more details

The log says:

Uncaught error while executing algorithm Traceback (most recent call last): Traceback (most recent call last): File "C:/PROGRA~1/QGISCH~1/apps/qgis/./python/plugins\processing\core\GeoAlgorithm.py", line 217, in execute self.processAlgorithm(progress) File "C:/PROGRA~1/QGISCH~1/apps/qgis/./python/plugins\processing\algs\qgis\AddTableField.py", line 75, in processAlgorithm self.getParameterValue(self.INPUT_LAYER)) File "C:/PROGRA~1/QGISCH~1/apps/qgis/./python/plugins\processing\tools\dataobjects.py", line 215, in getObjectFromUri print _loadedLayers IOError: [Errno 9] Bad file descriptor

After a few hours I tried to run the model again without changing anything and then this error appeared: Error executing algorithm 6 [Errno 9] Bad file descriptor See log for more details

In the log the same explanation as above.

Can anyone help me understand what's happening here?

  • I did a test and it worked fine for me. For your final algorithm, enter a name for the Output layer. When you run the model, you will be prompted to output the final layer as a temporary layer or save it in a directory (whichever you want). See if this works.
    – Joseph
    Commented Jan 22, 2015 at 11:26
  • Hi Joseph, In my initial model I already gave a name for the outputlayer in my final algorithm. I think it has something to do with the temporary files the model create during the process. When I empty /appdata/local/temp/processing, the error appears later on in the process (around 10th algrorithm).
    – PieterB
    Commented Jan 23, 2015 at 8:11

1 Answer 1


I installed version 2.6.1 and now the model works without problems.


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