@AksyA16614715

Data page load activities must have an applies to class that is the same as the class of the data page.

If the data page is page mode then the activity must be the in the same class as the data page.

If the data page is of list type then the activity must be defined in Code-Pega-List and populate the pxResults page list.

In your activity to source a list data page, you have to populate the Primary.pxResults page list.

Set Primary.pxResults class on the Pages & Classes tab of the activity (should be the same as,  or a descendant class of the one given on the data page rule) and in the steps you can then populate the page list.

Hi @AksyA16614715,

There are two options. Kindly choose the one which is pretty well-suited with your requirement. Kindly try both and let me know the result whether it works or not.

1. If you need to absolutely use List structure for your DP, you have to create activity under Code-Pega-List class let's say to create populateMyEntityList activity associate it with your DP and check in your data page. You can refer and call activity from another class under populateMyEntityList like below. You can consider DMORg-DMSample-Data is Org-Div-Unit-Work for your scenario. 

2. If you are not going to associate your list structured data page with some Dropdown picker or table's source in any section, you can configure your data page structure as Page and populate the .pxResults page list property of Org-Div-Unit-Work class. (Org-Div-Unit-Work is the object type of your DP) then you can iterate over D_YourDataList.pxResults from where you need this dataset.