While i was experimenting with Upfront - spirit editing theme.
its also issue to switch back to normal edits after responsive mode,
after few edits when i click on leave man icon ( left menu sidebar top right )
then it asked for reload page confirmation and leave page confirmation,
then it went to site sql file and not found error, then sql file get download in browser automatically. iT was complete db file with data, that is much more serious threat security concern rather functionality bug.
see screen shot ..
Please look into these issue