The Blend constantly leaks memory when a form with a progress bar is opened in design or split view, and the current theme is PresentationFramework.Aero .

Closing the view stops the leak, but does not release memory until Blend is closed.

The Blend leaks memory memory at approximate rate 160K/sec/instance, which is quickly consumes all available memory.

The problem appears to be associated with progress bar animation. Redefining the style or applying a different theme, that does not contain animation, resolves the problem.