I have 198 tiles of a DEM from which I want to extract contour lines, but doing the operation 198 times is ungainly.
I tried SAGA's Merge raster layers, but it stops into this error:
Oooops! The following output layers could not be open Merged Grid: C:\Users\USER\AppData\Local\Temp\processing\9833d17c1e3845ddbd7717b1c3084920\MERGED.tif The above files could not be opened, which probably indicates that they were not correctly produced by the executed algorithm Checking the log information might help you see why those layers were not created as expected This algorithm requires SAGA to be run. A test to check if SAGA is correctly installed and configured in your system has been performed, with the following result: SAGA seems to be correctly installed and configured
The Python error in the message log says:
2016-05-22T17:59:45 1 Traceback (most recent call last): File "C:/Users/USER/.qgis2/python/plugins\processing\gui\ProcessingToolbox.py", line 191, in executeAlgorithm dlg = ParametersDialog(alg) File "C:/Users/USER/.qgis2/python/plugins\processing\gui\ParametersDialog.py", line 42, in __init__ AlgorithmExecutionDialog.__init__(self, alg, self.scrollArea) File "C:/Users/USER/.qgis2/python/plugins\processing\gui\AlgorithmExecutionDialog.py", line 110, in __init__ isText, help = self.alg.help() File "C:/Users/USER/.qgis2/python/plugins\processing\algs\saga\SagaAlgorithm.py", line 510, in help name + '.rst')) File "C:/Users/USER/.qgis2/python/plugins\processing\gui\Help2Html.py", line 55, in getHtmlFromRstFile print s IOError: [Errno 9] Bad file descriptor
Similarly, trying GDAL > Miscellaneous > Merge also results in a Python crash, with no log.
An older question seemed to have a similar error, but was fixed by manually downloading the most recent SAGA. I did this, and the error did not change.