Error "The feature being activated is a Site Collection scoped feature ... Please activate the following feature before trying again"
In SharePoint, the following error might occur, even if the Forms feature has been previously activated:
The feature being activated is a Site Collection scoped feature which has a dependency on a Web Application scoped feature which has not been activated. Please activate the following feature before trying again: Nintex Forms 2010 0cdf436f-61b0-43d2-b250-4360f0353b63
Go to: SharePoint Central Administration > Application Management > Manage Web Applications.
Left click the row that your web application is in and from the ribbon select "Manage Features".
Locate the "Nintex Forms 20XX" listing and select the "Activate" button.
NOTE: This process will trigger an app pool refresh.