I have tried to use the Processing Toolbox in QGIS 2.0.1 a couple of times now (using SAGA and OTB) and in both cases the processing tools always return an error along these lines:
"Problem loading output layers: The following output layers could not be open(ed) - Output image: D:/Temp/output.tif
The above files could not be opened, which probably indicates that they were not correctly produced by the executed algorithm. Checking the log ... etc."
When I dismiss the error the original tool's window also closes, giving me no opportunity to check the log.
This is a brand new Windows 8 installation with a brand new QGIS installation (via the OSGeo4W online installer). D: is writeable and I have set up folders for the OTB toolbox.
What else should I do to get these toolboxes to work?