TOPS coregistration problem


I am trying to re-do an interferometry turorial to my chosen area based on this tutorial:

I have a dataset from 2015 and 2019, they are both S1A - IW - SLC format.
However, after TOPS coregistration finishes, the slave intensity band is always a grey blank image

The setting of the TOPS coregistration are the same as in the tutorial

If I try to make the next step, which is Interferogram Formation, the following error pops up:

I don’t know if this is because of the coregistration or just another totally independent error.

My question is what am I doing wrong and why is it not working.

Thanks for the help in advance!

Try to use SRTM HD 1sec auto-download instead of 3sec, and check this box

after back-geocoding apply ESD, Enhanced Spectral Diversity,

Similar issue is discussed here,

problem occurred during target product initialization

Thank You! It worked.

May I ask the thought process behind your answer? I want to improve