Getting "STG_E_FILENOTFOUND" when creating project using project template wizard

I am trying to create a VSIX project for creating multi-project template using Wizard but I am getting exception on

this.dte.Solution.AddFromTemplate(Path.Combine(this.templateDirectory, "WebTemplate\\UI.vstemplate"), Path.Combine(this.solutionDirectory,  this.projectName), this.projectName, false);  

Exception is

"could not be found. (Exception from HRESULT: 0x80030002 (STG_E_FILENOTFOUND))"

Stack trace is:

at EnvDTE.SolutionClass.AddFromTemplate(String FileName, String Destination, String ProjectName, Boolean Exclusive)

at TemplateWizard.RootWizard.ProjectFinishedGenerating(Project project)