Open in Excel - Publish button not enabled - Dynamics 365 operations

Hi,

My new form has the Primary data source as ReqItemTable and the child datasources as InventDim/ReqGroup.

As per the client requirement, there is a need to have “Open in Excel” functionality in this form.

So I created a data entity with ReqItemTable as Primary data source and added the remaining datasources (InventDim/ReqItemGroup) to the data entity.

I mapped the needed fieds in AUTO REPORT.

Now I get the option “Open in Excel” in my form and I could export the fields succesfully.

But the button “Publish” is disabled .

Did I miss something when I created the entity ?