How many times can I call gtk_label_set_markup()?

[Igor Korot <ikorot01 gmail com>]

Hi, ALL,
I need to change the markup text in the label conditionally in the loop.
However, I'm getting this on the second call of gtk_label_set_markup():

(mini2440gtk:19672): GLib-GObject-WARNING **: invalid cast from
`(null)' to `GObject'

(mini2440gtk:19672): GLib-GObject-CRITICAL **: g_object_freeze_notify:
assertion `G_IS_OBJECT (object)' failed

(mini2440gtk:19672): GLib-GObject-WARNING **: invalid cast from
`(null)' to `GObject'

(mini2440gtk:19672): GLib-GObject-CRITICAL **: g_object_notify:
assertion `G_IS_OBJECT (object)' failed

(mini2440gtk:19672): GLib-GObject-WARNING **: invalid cast from
`(null)' to `GtkWidget'

(mini2440gtk:19672): Gtk-CRITICAL **: gtk_widget_queue_resize:
assertion `GTK_IS_WIDGET (widget)' failed

(mini2440gtk:19672): GLib-GObject-WARNING **: invalid cast from
`(null)' to `GObject'

(mini2440gtk:19672): GLib-GObject-CRITICAL **: g_object_thaw_notify:
assertion `G_IS_OBJECT (object)' failed

I checked and the window and the text are both not NULL.

Is it possible to do it this way? Or I just need to dereference something?

Thank you.