Argh! Something went wrong and a serious error occurred:

Internal GStreamer error: clock problem.  Please file a bug at http://bugzilla.gnome.org/enter_bug.cgi?product=GStreamer.

gstpipeline.c(568): gst_pipeline_change_state (): /timeline:
Pipeline cannot operate with selected clock

It is recommended that you report this to the Jokosher developers or get help at http://www.jokosher.org/forums/