Mountain Lion and LibreOffice Spreadsheets.

I’m really exasperated because I just can’t get the LO Spreadsheets to open in Mountain Lion.

Yesterday I had it open and running on an external USB stick, completed some spreadsheet work then saved it and dragged the USB stick icon off the desktop to ensure all my work has been saved.

Today it’s impossible to open the same item because it just ‘flashes’ once and disappears.

Please help me because I’m desperate to continue my work on it.

Thank you.