         @latex_editor.remove()
         @element.remove()
         @preview.remove()
-        @preview_embed.remove()
+        @preview_embed?.remove()
 
     _init_buttons: () =>
         @element.find("a").tooltip(TOOLTIP_CONFIG)

        @latex_editor.on 'saved', () =>
            @update_preview () =>
                if @_current_page == 'pdf-preview'
                    @preview_embed.update()
            @spell_check()

        @latex_editor.syncdoc.on 'connect', () =>

            if not err
                @update_preview (force=force) =>
                    if @_current_page == 'pdf-preview'
                        @preview_embed?.update()
                @spell_check()

    update_preview: (cb, force=false, only_compile=false) =>
