I have started with ASP.NET 5 and just updated to RC (VS2015). By my start, I have placed some central methods and data-definitions in the startup.cs-file (where I don’t have problems with it).
Now, I want to use an own class-file for my own code and therefore have added a new class-file to the project (in VS) and copy-pasted my code from startup.cs in my own class file (and commented the code in startup.cs of course).

Now, I have duplicate definitions of the methods to themselves. Error e.g.:

M:\SW\VS_2015\WEB\MGTest2\src\MGTest2\ZentraleFunktionenVariablen.cs(280,52,280,76): DNX Core 5.0 error CS0121: The call is ambiguous between the following methods or properties: 'ZentraleFunktionenVariablen.MG_Funktionen.GetDynamicIdentification(DateTime)' and 'ZentraleFunktionenVariablen.MG_Funktionen.GetDynamicIdentification(DateTime)

In the error-window, I can see two projects in the project column:
MGTest2.DNX 4.5.1
MGTest2.DNX Core 5.0

So… it seems, as the methods are registered for the two runtimes, what causes the problem and some other configurations has to be done to solve the problem. I don’t have found any information to the problem yet.

Note: The class-file is stored in the root to the project (where also startup.cs is stored). I have tried to store the file in an own project-directory, what not solves the problem.