I don't have the actual solution. However, I can give you some tips and see
if they work and let us know.
Have you check all the buttons or is there any toolbar in your breifcase?
If there is no toolbar then click View - Toolbar - Standard Button - and
check the Update All button (with no title).
If that doesn't works then try creating a new briefcase on your desktop and
see if the context menu is there. If it is then transfer your files to that
briefcase. I think it will be the simple solution.
If it works then let us know.