SNAP 8.0.2 - Sentinel 1 Terrain Correction step hangs

Hi, I am using SNAP v 8.0.2. When processing Sentinel GRD IW data, I am having problem with the final Terrain Correction step (Radar/Geometric/Terrain Correction/Range-Doppler TC). It starts processing the data but then the process hangs. Sometimes the process has completed but Processing dialogue screen (progress bar) just hangs. The only non-default setting I use is the projection, which is set to UTM36S. Am I missing something? Thanks very much. Mark

this has been reported and solved here: SRTM ZIP-files are corrupted or not found