Using5.16.2 on an ubuntu touch device, the telepathy-mission-control-5 issues regular warnings "signal id '%u' is invalid for instance"

backtrace of one of the warnings

"#0  g_log (log_domain=0xb6c44a08 "GLib-GObject", 
    log_level=log_level@entry=G_LOG_LEVEL_WARNING, 
    format=0xb6c49644 "%s: signal id '%u' is invalid for instance '%p'")
    at /build/buildd/glib2.0-2.41.5/./glib/gmessages.c:1075
#1  0xb6c36eb8 in g_signal_emit_valist (instance=0xbe864e40, signal_id=33, 
    detail=3196472896, detail@entry=0, var_args=..., var_args@entry=...)
    at /build/buildd/glib2.0-2.41.5/./gobject/gsignal.c:3101
#2  0xb6c37668 in g_signal_emit (instance=<optimized out>, 
    signal_id=<optimized out>, detail=0)
    at /build/buildd/glib2.0-2.41.5/./gobject/gsignal.c:3365
#3  0xb6ca5d92 in marshal_dbus_message_to_g_marshaller (closure=0x5f28e8, 
    return_value=0x0, n_param_values=<optimized out>, 
    param_values=<optimized out>, invocation_hint=0xbe864fb8, marshal_data=0x0)
    at dbus-gproxy.c:1736
#4  0xb6c245b4 in g_closure_invoke (closure=0x5f28e8, return_value=0x0, 
    n_param_values=3, param_values=0xbe865000, invocation_hint=0xbe864fb8)
    at /build/buildd/glib2.0-2.41.5/./gobject/gclosure.c:768
#5  0xb6c310aa in signal_emit_unlocked_R (node=node@entry=0x5eb2a0, 
    detail=457, detail@entry=0, instance=0x5ec428, instance@entry=0x5f6dd0, 
    emission_return=emission_return@entry=0x0, 
    instance_and_params=instance_and_params@entry=0xbe865000)
    at /build/buildd/glib2.0-2.41.5/./gobject/gsignal.c:3553
#6  0xb6c37462 in g_signal_emit_valist (instance=instance@entry=0x5ec428, 
    signal_id=<optimized out>, detail=detail@entry=0, var_args=..., 
    var_args@entry=...)
    at /build/buildd/glib2.0-2.41.5/./gobject/gsignal.c:3309
#7  0xb6c37668 in g_signal_emit (instance=instance@entry=0x5ec428, 
    signal_id=<optimized out>, detail=457)
    at /build/buildd/glib2.0-2.41.5/./gobject/gsignal.c:3365
#8  0xb6ca637e in dbus_g_proxy_emit_remote_signal (message=<optimized out>, 
    proxy=0x5ec428) at dbus-gproxy.c:1789
#9  dbus_g_proxy_manager_filter (connection=<optimized out>, 
    message=<optimized out>, user_data=0x5eb500) at dbus-gproxy.c:1356
#10 0xb6c6b2e2 in dbus_connection_dispatch ()
   from /lib/arm-linux-gnueabihf/libdbus-1.so.3
#11 0xb6ca22ac in message_queue_dispatch (source=<optimized out>, 
    callback=<optimized out>, user_data=<optimized out>) at dbus-gmain.c:90
#12 0xb6b79f50 in g_main_dispatch (context=0x5cd9b8)
    at /build/buildd/glib2.0-2.41.5/./glib/gmain.c:3064
#13 g_main_context_dispatch (context=context@entry=0x5cd9b8)
    at /build/buildd/glib2.0-2.41.5/./glib/gmain.c:3663
#14 0xb6b7a0fc in g_main_context_iterate (context=0x5cd9b8, 
    block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /build/buildd/glib2.0-2.41.5/./glib/gmain.c:3734
#15 0xb6b7a398 in g_main_loop_run (loop=0x5d12d8)
    at /build/buildd/glib2.0-2.41.5/./glib/gmain.c:3928
#16 0x0001d05a in mcd_service_run (self=<optimized out>) at mcd-service.c:190
#17 0x0001ba2c in main (argc=<optimized out>, argv=<optimized out>)
    at mc-server.c:194"