Hi Marco,
thank you for all the information.
I was able to reproduce the error.
This seems to be related to the maximum number of groups that NetCDF can handle, which is exceeded here. It was adressed already in SNAP-3509
I believe you actually were the one identifying this.
The workaround is to delete the metadata element
“Level-1C_DataStrip_ID/Satellite_Ancillary_Data_Info”
This worked for me.