Today, I've run into an error after updating my mozilla and firefox packages using the APT system. Investigating the situation, I found a solution which I like to share. First I updated to MozillaFirefox-1.0-4.3 apt install MozillaFirefox - installed version 1.0-4.3 When calling the app: /usr/bin/firefox it resulted in the error message /mozilla-bin: error while loading shared libraries: /opt/gnome/lib/libpangoft2-1.0.so.0: undefined symbol: g_type_class_add_private Googling for the error message only reveiled a discussion on this board from September last year, suggesting to reload the original version from the CD. My personal solution: Looking into the directory /opt/gnome/lib reveils two broken symbolic links: libglib-2.0.so -> libglib-2.0.so.0.400.6, libgmodule-2.0.so -> libgmodule-2.0.so.0.400.6 After fixing these links, mozilla & firefox are working fine. These are my changes (as root user): cd /opt/gnome/lib rm libglib-2.0.so && ln -s libglib-2.0.so.0.400.7 libglib-2.0.so rm libgmodule-2.0.so && ln -s libgmodule-2.0.so.0.400.7 libgmodule-2.0.so Regards, Rainer