Math Character does no show

Dear All,

Recently Debian 8 was updated and maybe a coincidence or not but the files that I had (Impress) that had math equations, now, when I edit or add new ones they are not visible anymore.

To make them visible I have to copy the equation to a new presentation and copy back to the original file.

Does someone have the same issue? Version under Gnome 3 Debian 8

All the best