Any idea how to fix these? I'm getting these "randomly" a third or fourth time I run my program on some systems: Pango-WARNING **: failed to create cairo scaled font, expect ugly output. the offending font is 'DejaVu Sans Mono 18' ** Pango:ERROR:/build/buildd/pango1.0-1.28.0/pango/pango-ot-buffer.c:346:pango_ot_buffer_output: assertion failed: (face) (rtEyeTracker:1899): Pango-WARNING **: font_face status is: invalid matrix (not invertible) (rtEyeTracker:1899): Pango-WARNING **: scaled_font status is: invalid matrix (not invertible) Aborted I'm using three gsttimeoverly elements and setting some static text labels using the "text" properties of the elements. I'm using default fonts and sizes. It seems pretty random as usually when restarting the program it doesn't happen next time. Is there something I need to do when shutting down my pipeline to prevent this the next time the program runs?