subject says it all
Happens with the cvs version.
This is not an xfce warning, but a GTK one. Something with the theme cannot be found. Try using a different one.
I understand that this is a gtk warning but it only happens under xfce. It doesn't matter which theme I use. Do you get this warning too? I tried searching google for this, but the only document containing this warning was the following: http://lunar-linux.org/pipermail/xfce-bugs/2004-June/000918.html
Hi! I've found out what causes this warning. Select the "defaut" icon theme in User Interface -> Icon theme.
I still don't think this is an xfce bug. Do you have the hicolor icon theme installed?
Yesterday I updated Xfce4 and still get this error when default icon theme is selected. I have dev-libs/glib-2.4.7 and x11-libs/gtk+-2.4.9. I installed Xfce4 to /usr/local so I have a hicolor theme in /usr/local/share/icons/ and one in /usr/share/icons as a part of gnome (I guess). Can this cause the problem? An interesting detail: tyr removing/renaming .config and .cache and start Xfce4. Go to User Interface -> Icon Theme. You will see that the 'hicolor' theme is selected. Select an other theme for example Rodent. Logout, login, and check the icon theme settings again. You will see that the hicolor theme disappeared from the list. Don't know whether this is related to my problem but seems a bit odd to me.
Ok, I looked at the gtk source and apparently GTK will complain when the icon theme you selected has no 'Name' field in its index.theme file. So, please check your hicolor theme. My hicolor theme does have a name field, btw.
This bug is either in your distribution, or in gtk. There's nothing Xfce can do about it.