Cannot Update UDO Lines Table via DTW

Hi experts,

We want to update a UDO viaData Transfer Workbench.

We are trying to add the templates for Header and Lines Table but we are facing the following issue:

When we import only the header template, the records are successfully introduced, but when we import the header and lines template together (with the correct parent key), only records for Header Table are successfully introduced.

Any advice would be appreciated.

Kind Regards

Vasilis Korolis