Your source code is missing CMS.PageTemplates folder and it is coming from Kentico 12.0.29 SP installation. [Kentico 12 SP introducing PageTemplates module for MVC]. I replicated in my local renaming the CMS.PageTemplates folder under CMSScripts->CMSModules and I am getting same experience.
Note: Please copy CMS.PageTemplates folder from your existing Kentico 12 SP instance to your current project (which was getting error) if any. Or install new Kentico 12 SP website.