Tell us about the problem

Frame.topmost() generally returns the last frame that performed navigation. However, with ns-4.0 there is a scenario where you can open a modal dialog with frame inside (and presumably navigate within the modal). Then at some point you close the modal dialog -- the unexpected behavior is that if you call Frame.topmost() at this moment it will return the frame from the modal dialog (that is actually unloaded) -- it should return the host frame or undefined.

Which platform(s) does your issue occur on?

Both

Please provide the following version numbers that your issue occurs with:

• CLI: 3.4.1
• Cross-platform modules: 4.0.0