Can't delete all notes.

[Epic music gay]

Whenever I select all notes in a sequence by pressing the button in the menus, Firefox (which is what I use) asks me if I want to go back to the previous page. I can't select cancel and press backspace to delete them all because it brings up the popup asking if I want to go to the previous page again. I don't know if it can happen in online sequencer, it has only happened in Offline sequencer. This is a huge bug that needs to get fixed.