Comment 4 for bug 846660

I did more testing and turned out that the matter is more serious than just the 'gtk-close'. I fixed that and now I started getting more errors:

(Pinta:25647): Gtk-WARNING **: Could not find the icon 'gtk-dialog-error'. The 'hicolor' theme
was not found either, perhaps you need to install it.
You can get a copy from:
 http://icon-theme.freedesktop.org/releases
GLib.GException: Icon 'gtk-dialog-error' not present in theme
  at Gtk.IconTheme.LoadIcon (System.String icon_name, Int32 size, IconLookupFlags flags) [0x00000] in <filename unknown>:0
  at Pinta.ErrorDialog.Build () [0x00000] in <filename unknown>:0
  at Pinta.ErrorDialog..ctor (Gtk.Window parent) [0x00000] in <filename unknown>:0
  at Pinta.MainClass.ExceptionManager_UnhandledException (GLib.UnhandledExceptionArgs args) [0x00000] in <filename unknown>:0
  at GLib.ExceptionManager.RaiseUnhandledException (System.Exception e, Boolean is_terminal) [0x00000] in <filename unknown>:0

As you suspected, the issue is more with the gtk# itself. I don't know how to install gtk theme in Mac. Any help? I can then do some testing.