What is the problem?

Question

After running raster>conversion>polygonize (raster to vector)I was given the following message in qgis 3.4.4. What should I do?

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Processing algorithm…
Algorithm 'Polygonize (raster to vector)' starting…
Input parameters:
{ 'BAND' : 1, 'EIGHT_CONNECTEDNESS' : False, 'FIELD' : 'DN', 'INPUT' : 'D:/Mics mentes/QGIS/Ausztrália/Asian_Islands.tif', 'OUTPUT' : 'C:/Users/User/AppData/Local/Temp/processing_5235d3ef5abb4c8a92127705c52838d0/d0d084b5fc684e0c9012c11a228a5a3f/OUTPUT.shp' }

GDAL command:
cmd.exe /C gdal_polygonize.bat "D:\\Mics mentes\\QGIS\\Ausztrália\\Asian_Islands.tif" C:/Users/User/AppData/Local/Temp/processing_5235d3ef5abb4c8a92127705c52838d0/d0d084b5fc684e0c9012c11a228a5a3f/OUTPUT.shp -b 1 -f "ESRI Shapefile" DN
GDAL command output:
'C:\PROGRA~2\QGIS' is not recognized as an internal or external command, operable program or batch file.

ERROR 4: `D:\\Mics mentes\\QGIS\\Ausztrlia\\Asian_Islands.tif' does not exist in the file system, and is not recognized as a supported dataset name.

Unable to open D:\\Mics mentes\\QGIS\\Ausztrlia\\Asian_Islands.tif

Execution completed in 7.67 seconds
Results:
{'OUTPUT': <QgsProcessingOutputLayerDefinition {'sink':C:/Users/User/AppData/Local/Temp/processing_5235d3ef5abb4c8a92127705c52838d0/d0d084b5fc684e0c9012c11a228a5a3f/OUTPUT.shp, 'createOptions': {'fileEncoding': 'System'}}>}

Loading resulting layers
The following layers were not correctly generated.<ul><li>C:/Users/User/AppData/Local/Temp/processing_5235d3ef5abb4c8a92127705c52838d0/d0d084b5fc684e0c9012c11a228a5a3f/OUTPUT.shp</li></ul>You can check the 'Log Messages Panel' in QGIS main window to find more information about the execution of the algorithm.

Answer 1

Probably try to rename the file and/or location/path without non-ASCII character, e.g. á, blanks etc. Save your input file direct in C:/ and save your output direct to C:/, if your user name contain a special character, try it with a guest account In my experience non-ASCII characters in file names or user names can cause such errors