User feedback when remove from album fails

When you have an image in a stack, and want to remove it from an album, Lr does nothing (silent failure) and provides no feedback.

Steps to repeat.

Add an image to a stack.

Select just the image using a filter, and not the complete stack.

Press delete.

Nothing happens.

Expected: either remove the image from stack and the album. Or tell the user why unable to remove the image.