I upgraded the application 10 to 11 version, after upgrade I cleaned the application and Rebuild the application.
I am getting below error message.
Could not load type 'CMS.Ecommerce.Web.UI.CMSPaymentGatewayProvider' from assembly 'CMS.Ecommerce.Web.UI, Version=11.0.0.0, Culture=neutral, PublicKeyToken=834b12a258f213f9'.
Please find the attached screenshot.