Which interface should I implement for supporting "Save Project as..." when "save new projects when created" is disabled/not checked?

Hej hej,

can someone tell me which interface I have to implement for supporting this dialog for my own project type:

I already have implement these interfaces:

	public abstract partial class ProjectNode :
		TcHmiHierarchyNode,
		ITcHmiProjectNodeBase,
		IVsGetCfgProvider,
		IVsProject3,
		IVsAggregatableProject,
		IVsProjectFlavorCfgProvider,
		IPersistFileFormat,
		IVsProjectBuildSystem,
		IVsBuildPropertyStorage,
		IVsComponentUser,
		IVsDependencyProvider,
		IVsSccProject2,
		IBuildDependencyUpdate,
		IProjectEventsListener,
		IProjectEventsProvider,
		IVsProjectSpecialFiles,
		IVsProjectUpgrade,
		IVsDesignTimeAssemblyResolution,
		IVsSetTargetFrameworkWorkerCallback
	{
[snip]
}

And these:

public class OAProject : EnvDTE.Project, ISupportVSProperties {}

But no breakpoint is hit and I always get this error message:

Cheers

Christian