Visual Studio 2015 error

I have a problem with creating of Telerik test studio project in VS 2015. After creating the project I cannot open the example.ttest file.
I get this error:

Severity Code Description Project File Line Suppression State
Warning The "GenerateElementsTask" task was not found. Check the following: 1.) The name of the task in the project file is the same as the name of the task class. 2.) The task class is "public" and implements the Microsoft.Build.Framework.ITask interface. 3.) The task is correctly declared with <UsingTask> in the project file, or in the *.tasks files located in the "C:\Program Files (x86)\MSBuild\14.0\bin" directory. TestStudioProject6
Severity Code Description Project File Line Suppression State
Warning IDE0006 Error encountered while loading the project. Some project features, such as full solution analysis for the failed project and projects that depend on it, have been disabled. TestStudioProject6 1 Active


Severity Code Description Project File Line Suppression State
Warning The referenced component 'Telerik.WebAii.Controls.Xaml' could not be found. TestStudioProject6
Warning The referenced component 'System.Windows.Forms' could not be found. TestStudioProject6
Warning The referenced component 'Telerik.WebAii.Controls.Html' could not be found. TestStudioProject6
Warning The referenced component 'ArtOfTest.WebAii.Design' could not be found. TestStudioProject6
Warning The referenced component 'ArtOfTest.WebAii' could not be found. TestStudioProject6
Warning The referenced component 'Telerik.TestingFramework.Controls.KendoUI' could not be found. TestStudioProject6
Warning The referenced component 'Microsoft.VisualStudio.QualityTools.UnitTestFramework' could not be found. TestStudioProject6
Warning The referenced component 'System.Core' could not be found. TestStudioProject6
Warning The referenced component 'System' could not be found. TestStudioProject6

I also get this error after trying to open the .ttest file:

the document cannot be opened. it has been renamed deleted or moved