Error with graphical modeler QGIS "not all arguments converted during string formatting"

Question

I'm new to QGIS Graphical Modeler. I've used ArcMap model builder before and now trying out the Graphical Modeler in QGIS2.18.15.

I tried creating a simple model where I create a buffer for a line feature (river) and then clip point data with the newly created buffer. I want to extract the points that are located within the buffer zone.

Everything seems fine but when I hit execute I get an error: "not all arguments converted during string formatting".

Can someone please explain what does this mean and how to fix this?

Traceback (most recent call last):
File "C:/PROGRA~1/QGIS2~1.18/apps/qgis/./python/plugins\processing\core\GeoAlgorithm.py", line 203, in execute
                self.processAlgorithm(progress)
File "C:/PROGRA~1/QGIS2~1.18/apps/qgis/./python/plugins\processing\modeler\ModelerAlgorithm.py", line 504, in processAlgorithm
                self.tr('Running %s [%i/%i]', 'ModelerAlgorithm') % (alg.description, len(executed) + 1, len(toExecute)))
            TypeError: not all arguments converted during string formatting

Answer 1

How to fix it

This is a bug in the Finnish translation affecting QGIS up to 2.18.15.

As a workaround switch to English or update to 2.18.16.

Explanation

The code of the modeller tries to create a message saying something like "Running (algorithm name) [50/100]". The Finnish translation provided an incomplete template for this message.

This has been fixed now so you will be able to use any upcoming version of 2.18 (2.18.16 and up) without this problem.