Lost navigation on left hand side of dashboard

I have currently upgraded to the new current upgrade but doing this has managed to swipe away the edit box (navigation / short cut) information on the left hand side of the dashboard.

This has occurred in most of my sites with different themes and I am able to access some of the information via the top bar instead. Have some information displayed within the dashboard itself but not enough to locate all my file information. Why does this occur…………

have very little technical skills. Please keep it simple…..
regards tony