I've seen this in 16.04 today (kernel 4.8):
Feb 18 06:27:03 lat61 gnome-session[3242]: compiz (core) - Info: Starting plugin: session Feb 18 06:27:03 lat61 gnome-session[3242]: I/O warning : failed to load external entity "/home/userX/.compiz/session/105f9b802130b2ad8c148739562211578000000032420003"
I've seen this in 16.04 today (kernel 4.8):
Feb 18 06:27:03 lat61 gnome-session[ 3242]: compiz (core) - Info: Starting plugin: session 3242]: I/O warning : failed to load external entity "/home/ userX/. compiz/ session/ 105f9b802130b2a d8c148739562211 578000000032420 003"
Feb 18 06:27:03 lat61 gnome-session[