Update Sharepoint designer form on adding new fields in the list

Hello All,

I was working on a SharePoint designer form where I needed to add new fields in the list.

After I added new fields in the list I need to update my designer form, but the problem is that “Add/Remove Columns” button in Data View Tools is disabled and hence I am not able to update my designer form. Have anybody ever had this problem?

Could it be a permission issue? (Currently I am accessing the site by Site collection administrator account.)

Kindly help!

Thanks,

Ruchika