GStreamer encountered a general stream error.

gstbasesrc.c(1642): gst_base_src_loop (): /timeline/playbackbin/Instrument_0/gnlcomposition0/gnlsource0/audiotestsrc1:
streaming task paused, reason not-linked (-1)

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