Error When Running JBE - My Fault

I had been successfully using my machine as a build engine. However, I had to make some changes in order to accommodate some additional required (not by RTC) tooling on that machine, and I seem to have broken JBE.

(A change that seems to me a likely candidate for being the delta that is causing JBE to no longer work: one of the new tools required stdglbc++5. My machine originally had stdglbc++6 when JBE was working. It now has both *5 and *6.)

The command I'm entering is:
./jbe -repository https://my.repository:9443/jazz -userId myid@mydomain.com -pass yeahRight -engineId "MyEngine Identifier"

Here are excerpts of the error:

(.:12372): GLib-GObject-WARNING **: invalid (NULL) pointer instance

(.:12372): GLib-GObject-CRITICAL **: g_signal_connect_data: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed

(.:12372): Gtk-CRITICAL **: gtk_settings_get_for_screen: assertion `GDK_IS_SCREEN (screen)' failed

(.:12372): GLib-GObject-CRITICAL **: g_object_get: assertion `G_IS_OBJECT (object)' failed

(.:12372): GLib-GObject-WARNING **: value "TRUE" of type `gboolean' is invalid or out of range for property `visible' of type `gboolean'

(.:12372): Gtk-CRITICAL **: gtk_settings_get_for_screen: assertion `GDK_IS_SCREEN (screen)' failed

(.:12372): GLib-GObject-CRITICAL **: g_object_get: assertion `G_IS_OBJECT (object)' failed

(.:12372): Gtk-WARNING **: Screen for GtkWindow not set; you must always set
a screen for a GtkWindow before using the window

(.:12372): Gdk-CRITICAL **: gdk_pango_context_get_for_screen: assertion `GDK_IS_SCREEN (screen)' failed

(.:12372): Pango-CRITICAL **: pango_context_set_font_description: assertion `context != NULL' failed

(.:12372): Pango-CRITICAL **: pango_context_set_base_dir: assertion `context != NULL' failed

(.:12372): Pango-CRITICAL **: pango_context_set_language: assertion `context != NULL' failed