Include all tie-point grids at subsetting? Or output more informative error messages?

Background: I picked up a graph generated in February 2019, and wanted to run this again now. I have updated SNAP to the latest version before I use it.

In short, it performs the following to S1 GRDH data (my current test file is S1A_IW_GRDH_1SDV_20180109T160607_20180109T160632_020080_0223A7_C73C):
Apply Orbit File->Subset->Calibration->Terrain Flattening->Terrain Correction

Problem: It ends with the (not so informative) error message “java.lang.NullPointerException”.
By taking the graph apart and executing parts of it, and the following steps “manually” I’ve traced down at least one problem: the subset function implemented in a graph does not seem to copy all tie-point grids, which causes problems later. The Terrain-Flattening function complains that “Product without incidence angle tie point grid”. When I subset “manually” in SNAP, the incident_angle grid is copied as expected. (I use “copy meta data” in both cases.)

However, I am not sure this is the real problem, since when performing the following steps manually (and hence providing a dataset WITH incident_angle present), the “Terrain Flattening” instead ends with “java.lang.NullPointerException”, and no further explanations. Is there a more extensive error message available in some log file?

Any suggestions on how to progress?
My current SNAP version is 6.0.10 and I don’t know which I used in February.

It might be that new parameters were add for terrain flattening and they don’t exist in the older graph.
You could recreate the graph or try inserting missing parameters like