Comment # 3 on bug 910343 from Martin Vidner

I can reproduce it on 13.2, pressing Alt-R once during the start up.
y2log says:
[ui] YDialog.cc(deleteTopmostDialog):550   THROW:    No dialog existing

It can be reproduced with ncurses *and* qt with this simple script which closes
more dialogs than it opens:

-- foo.rb
require "yast"
module Yast
  import "UI"
  UI.CloseDialog
end
--

# yast2 ./foo.rb

So I think the problem is in bootloader code. It should match closing dialogs
with opening them.