I've been reading as many posts as I could for hours but the answers never match my problem:
I have a main list that contains all the necessary fields that are partially copied into several other lists in different sites.
What I want to do is when a user modifies one or several fields in his own site list, it updates the fields in the main list.
About 20 fields can be modified so I am updating all the fields in the same time whether they are filled or not (is there a better solution?).
Now, I created one same ID for the item that is copied in each list. But when I use the Update multiple items action, I get an error "Object reference not set to an instance of an object."
Yet, I used the filter so it modifies the field when the item ID equals the main list item ID :
Sorry it is in French but I think you will understand.
I thought about creating a condition for each field but I don't like this solution.
I also thought about using the Call web service action but I am not handling well the web service and did not find complete documentation about it. My SDK doc file only shows me one method...
I hope I was clear enough, don't hesitate to tell me if you need more information. I am working on SharePoint 2010 with nintex workflow 2010.