Issue
When creating a site in Project Server using the project site template that includes Nintex Workflow and Nintex Forms the below error occurs.
Error message: Create Web Site Operation Failed
Error message: Create Web Site Operation Failed
Resolution
Creating a site template in SharePoint that includes Nintex Workflow and Nintex Forms and then creating a site in Project Server using the site template is not supported. Nintex Workflow and Nintex forms for SharePoint on-premise are not compatible with Project Server.