DEM Assisted Coregistration with XCorr - StackOverflowError

Hi everyone,
I was trying to coregister an ascending and descending image (GRD) using the “DEM assisted coregistration with XCorr” function.
When I leave all the default settings it works (the results are not that good though). When I change the settings the DEM to “SRTM 1Sec Grid” or “SRTM 1Sec HGT (auto download)” I get following error:

I want to mention that I extracted the dem files from SRTM (USGS) to the .snap\auxdata\dem\SRTM 1Sec Grid folder.

Why does the error pop up?

-At this point I would like to ask another short question. When is it recmommended to use the “Coherence based registration” and why is it not possible to adjust other parameters in the “Fine Registration” area in the “Cross-Correlation” tab?

Best regards,

You shouldn’t need to download and extract your own dem tiles for SRTM. SNAP will automatically download the tiles needed for your scene. I’m not sure if the problem is related to the tiles from USGS. Maybe they’re not in the zipped HGT format expected.

The fine registration is for complex SLC data. Your data is GRD.