Custom baseclass is defined in an external DLL with the following info: The namespace of the baseclass is: TestBaseClass Class name is: BaseTest which inherits 'BaseWebAiiTest' located in DLL: TestBaseClass\bin\Debug\TestBaseClass.dll Reference to TestBaseClass.dll is added to both the dotnet telerik project as well as the telerik project itself. it complaints about "there are no classes in code behind that extend the webaii base class 'TestBaseClass.BaseTest'" Expected behavior: to be compiled in Visual Studio and to be able to run a test in Test Studio Actual behavior: Visual Studio cannot compile the project, If a coded step is created in the Test Studio project it displays an error message It works as expected in version 2015_3_1314_2