How to add a data dictionary structure to a context node?

Hi,

I have created a massive context node based on attributes of a z table.

I then created my layout, table etc.

I now realise that I need to define the z table as a data dictionary structure, for the context node, otherwise quantities and amounts won't display properly.

Unfortunately when I try to do this I get this error message which says it will delete everything:

I think this will then break all the UI bindings I have done and will be a massive piece of work to put right.

Does anyone have any experience of this and how best to proceed?