When running the screensaver app Xscreensaver it displays the following errors:

xscreensaver: unable to find any alternatives to “-*-helvetica-bold-r-*-*-*-180-*-*-*-*-iso8859-1”
xscreensaver: unable to find any alternatives to “-*-helvetica-bold-r-*-*-*-140-*-*-*-*-iso8859-1”
xscreensaver: unable to find any alternatives to “-*-helvetica-bold-r-*-*-*-140-*-*-*-*-iso8859-1”
xscreensaver: unable to find any alternatives to “-*-helvetica-bold-r-*-*-*-140-*-*-*-*-iso8859-1”
xscreensaver: unable to find any alternatives to “-*-helvetica-medium-r-*-*-*-80-*-*-*-*-iso8859-1”
xscreensaver: unable to find any alternatives to “-*-helvetica-bold-r-*-*-*-120-*-*-*-*-iso8859-1”

This is due to creator of the Xscreensaver using a non-standard font in their application. It can be fixed by installing the following fonts.

sudo apt-get install t1-xfree86-nonfree ttf-xfree86-nonfree ttf-xfree86-nonfree-syriac xfonts-75dpi xfonts-100dpi

After reboot no more errors when the Xscreensaver runs.