Layers not correctly generated using SAGA algorithms within QGIS 3.4.4-Madeira

Question

I am trying to use a few algorithms that may be useful for my work, that are part of the processing tools packaged with the latest LTR 64-bit version of QGIS in Windows 10 64 bit.. However, all of the SAGA algorithms that I have tried so far throw the same final error, regarding layers that were not correctly generated. The following image is the end of the log message I get. In red is the error I mention. It happens with all tools I have tried so far.

I checked other posts and read similar issues. Some suggestions to fix it included using different paths, and avoiding blank spaces in them. I tried changing the path to a D:\Temp directory but no success.

Things I noticed:

• In the log, some paths appear with forward slash (/), as in Unix systems.
• Some long paths appear shortened, using the tilde (~). In particular, C:\OSGeo4W64 gets shortened to C:\OSGeo4~1

Any hints?

EDIT:

This is the output log provided in comments:

Procesando algoritmo...

Algoritmo 'Profiles from lines' comenzando…

Parámetros de entrada:

{ 'DEM' : 'F:/Dropbox/QGIS_Test/DEM.tif', 'LINES' : 'F:\\Dropbox\\QGIS_Test\\Lines.shp', 'NAME' : 'id', 'PROFILE' : 'C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/8d34e08d5a984c11a8ffce8b99fadd36/PROFILE.shp', 'PROFILES' : 'C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/acbe581a52b9406fb5db4af3292f919a/PROFILES.shp', 'SPLIT ' : True, 'VALUES' : '' }


io_gdal 0 -TRANSFORM 1 -RESAMPLING 3 -GRIDS "C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/635ead2d3ee34f7bbeda0d5905c407b0/DEM.sgrd" -FILES "F:\Dropbox\QGIS_Test\DEM.tif"

ta_profiles "Profiles from Lines" -DEM "C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/635ead2d3ee34f7bbeda0d5905c407b0/DEM.sgrd" -LINES "F:\Dropbox\QGIS_Test\Lines.shp" -NAME "id" -SPLIT true -PROFILE "C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/8d34e08d5a984c11a8ffce8b99fadd36/PROFILE.shp" -PROFILES "C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/acbe581a52b9406fb5db4af3292f919a/PROFILES.shp"


F:\Dropbox\QGIS_Test>set SAGA=C:/PROGRA~2/QGIS3~1.4/apps\saga-ltr


F:\Dropbox\QGIS_Test>set SAGA_MLB=C:/PROGRA~2/QGIS3~1.4/apps\saga-ltr\modules


F:\Dropbox\QGIS_Test>PATH=C:\PROGRA~2\QGIS3~1.4\apps\qgis\bin;C:\PROGRA~2\QGIS3~1.4\apps\Python37;C:\PROGRA~2\QGIS3~1.4\apps\Python37\Scripts;C:\PROGRA~2\QGIS3~1.4\apps\qt5\bin;C:\PROGRA~2\QGIS3~1.4\apps\Python27\Scripts;C:\PROGRA~2\QGIS3~1.4\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32\WBem;C:\PROGRA~2\QGIS3~1.4\apps\Python37\lib\site-packages\pywin32_system32;C:\PROGRA~2\QGIS3~1.4\apps\Python37\lib\site-packages\numpy\.libs;C:/PROGRA~2/QGIS3~1.4/apps\saga-ltr;C:/PROGRA~2/QGIS3~1.4/apps\saga-ltr\modules


F:\Dropbox\QGIS_Test>saga_cmd io_gdal 0 -TRANSFORM 1 -RESAMPLING 3 -GRIDS "C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/635ead2d3ee34f7bbeda0d5905c407b0/DEM.sgrd" -FILES "F:\Dropbox\QGIS_Test\DEM.tif"

____________________________


##### ## ##### ##

### ### ## ###

### # ## ## #### # ##

### ##### ## # #####

##### # ## ##### # ##

____________________________


SAGA Version: 2.3.2 (32 bit)


____________________________

library path: C:\PROGRA~2\QGIS3~1.4\apps\saga-ltr\modules\

library name: io_gdal

library : GDAL/OGR

tool : Import Raster

author : O.Conrad (c) 2007 (A.Ringeler)

processors : 8 [8]

____________________________




Parameters



Grids: No objects

Files: "F:\Dropbox\QGIS_Test\DEM.tif"

Select from Multiple Bands:

Alphanumeric Sorting: yes

Transformation: yes

Resampling: B-Spline Interpolation



loading: F:\Dropbox\QGIS_Test\DEM.tif




Driver: GTiff


Bands: 1


Rows: 5557


Columns: 7445



loading: DEM






F:\Dropbox\QGIS_Test>saga_cmd ta_profiles "Profiles from Lines" -DEM "C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/635ead2d3ee34f7bbeda0d5905c407b0/DEM.sgrd" -LINES "F:\Dropbox\QGIS_Test\Lines.shp" -NAME "id" -SPLIT true -PROFILE "C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/8d34e08d5a984c11a8ffce8b99fadd36/PROFILE.shp" -PROFILES "C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/acbe581a52b9406fb5db4af3292f919a/PROFILES.shp"

Error: dbf write: invalid table

____________________________


##### ## ##### ##

### ### ## ###

### # ## ## #### # ##

### ##### ## # #####

##### # ## ##### # ##

____________________________


SAGA Version: 2.3.2 (32 bit)


____________________________

library path: C:\PROGRA~2\QGIS3~1.4\apps\saga-ltr\modules\

library name: ta_profiles

library : Profiles

tool : Profiles from Lines

author : O.Conrad (c) 2006

processors : 8 [8]

____________________________


Load grid: C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/635ead2d3ee34f7bbeda0d5905c407b0/DEM.sgrd...



Load shapes: F:\Dropbox\QGIS_Test\Lines.shp...





Parameters



Grid system: 5; 5557x 7445y; 511960x 4649730y

DEM: DEM

Values: No objects

Lines: Lines

Name: id

Profiles: Profiles

Profiles: No objects

Each Line as new Profile: yes




failed

Save shapes: C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/acbe581a52b9406fb5db4af3292f919a/PROFILES.shp_1...



Save shapes: C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/acbe581a52b9406fb5db4af3292f919a/PROFILES.shp_2...




F:\Dropbox\QGIS_Test>exit

Ejecución completada en 12.90 segundos

Resultados:

{'PROFILE': 'C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/8d34e08d5a984c11a8ffce8b99fadd36/PROFILE.shp',
'PROFILES': 'C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/acbe581a52b9406fb5db4af3292f919a/PROFILES.shp'}


Cargando las capas resultantes

Las siguientes capas no se generaron correctamente.<ul><li>C:/Users/Kais/AppData/Local/Temp/processing_5080f69b88474281943ae5c46597245d/8d34e08d5a984c11a8ffce8b99fadd36/PROFILE.shp</li></ul>Puede comprobar el «Panel de mensajes del registro» en la ventana principal de QGIS para encontrar más información sobre la ejecución del algoritmo.  

Answer 1

There are some problems with the Profiles from lines algorithm in QGIS.

Let's see first how it should work.

In SAGA GIS, at the command line:

• If you want to save Each Line as a New Profile, you need to use the -SPLIT and the -PROFILES options. Files will be saved as profile_01.shp, profile_02.shp, etc.

• If not, don't use -SPLIT option and use -PROFILE option. File will be saved as profile.shp.

In QGIS processing toolbox:

• Both -PROFILE and -PROFILES options are always used, so one of them always returns an error (The following layers were not correctly generated.).

• If you tick on Each Line as a New Profile (is ticked by default), -SPLIT option is used, and the files are saved as PROFILE.shp1, PROFILE.shp2, etc. That produced two errors (one for the -PROFILE empty layer and other for the invalid extensions).

A bug report was already opened: https://issues.qgis.org/issues/21294.

Meanwhile, a possible workaround is to not use the Each Line as a New Profile option (untick it) and ignore the error generated by the -PROFILE over option.