Showing error messages when trying to get into unaccessible/nonexistent directory

[mikekazakov]

The following situation does not seem to be handled well.
Left pane shows directory /a/b/c
Elsewhere directory b is deleted
Afterward, clicking or hitting return in the left pane on the item .. [parent directory] does nothing, neither does it give an error.

It seems to me that some error or indication should be given.