Package: abiword Version: 3.0.2-2+deb9u1 I can change the font size by selecting with the mouse one of the predefined sizes in the scroll-down list.
I can not change the font size by entering the font size with the keyboard. This is necessary for chosing font sizes not listed in the scroll-down list. This might be a clue. Upon entering the font size with the keyboard, abiword prints to stdout: (abiword:7994): GLib-GObject-WARNING **: invalid cast from 'GtkBox' to 'GtkComboBox' (abiword:7994): Gtk-CRITICAL **: gtk_combo_box_get_model: assertion 'GTK_IS_COMBO_BOX (combo_box)' failed (abiword:7994): GLib-GObject-WARNING **: invalid cast from 'GtkBox' to 'GtkComboBoxText' (abiword:7994): Gtk-CRITICAL **: gtk_combo_box_text_get_active_text: assertion 'GTK_IS_COMBO_BOX_TEXT (combo_box)' failed (abiword:7994): GLib-GObject-WARNING **: invalid cast from 'GtkBox' to 'GtkComboBox' (abiword:7994): Gtk-CRITICAL **: gtk_combo_box_get_model: assertion 'GTK_IS_COMBO_BOX (combo_box)' failed (abiword:7994): GLib-GObject-WARNING **: invalid cast from 'GtkBox' to 'GtkComboBoxText' (abiword:7994): Gtk-CRITICAL **: gtk_combo_box_text_get_active_text: assertion 'GTK_IS_COMBO_BOX_TEXT (combo_box)' failed I created in January 2017 an abiword documents with font sizes not listed in the scroll-down list. Back then, abiword "was working". I'm using Linux debian 4.9.0-6-amd64 #1 SMP Debian 4.9.82-1+deb9u3 (2018-03-02) x86_64 GNU/Linux, libc 2.24-11+deb9u3 and libgtk-3-0 3.22.11-1.
