The main problem is that you are using SRTM 1 sec Grid which does not auto download. You need to have all the dem tiles in Arc Grid format.
Please use ‘SRTM 1Sec HGT’ and even then be careful about the coverage since most of the Middle East and some of Africa, Russia, Turkey, Greece are not covered. See here.
Also, your graph looks like it’s from S1TBX 1.1 Although it works, I would recreate any graphs in SNAP 2 to make sure any missing or renamed parameters are present. backgeocoding-productset.xml (2.1 KB)