DEM-assist sourceproduct error in processing graph

Dear SNAP developers and users,

I found a small problem with the DEM-assist operator when using this in a processing graph. If I want to do a simple processing with this graph:

I get the following error:

Operator 'WriteOp': Mandatory source product (field 'sourceProduct') not set.

However, doing a DEM coregistration using the toolbar (Radar -> Coregistration -> DEM-assisted coregistration -> DEM-assisted coregistration) it does work. I’ve tried to do some debugging in the code, but I can’t trace down to the place where the error occurs.

Kind Regards,