Gtk-WARNING **: Could not load a pixbuf from icon theme

Whenever I start firefox, steam, and some other gui programs from the terminal, I see this error.

I have searched for possible solutions to this problem, the most common one I found was sudo update-mime-database /usr/share/mime, which runs without printing any errors (or anything at all) for me, but does not change anything.

I tried changing permissions, as suggested here: How to repair broken permissions on files in /usr/share/mime?, however, this also changed nothing.

https://bbs.archlinux.org/viewtopic.php?id=245985

I have very similar issues (it occurs much more often when launched from the command line) to what is described in this arch forum post, however XDG_DATA_DIRS is not set in my .zshrc, nor does it have the flatpak path (it is /home/user/snap/alacritty/46/.local/share:/home/user/snap/alacritty/46:/snap/alacritty/46/usr/share:/usr/share/awesome:/usr/local/share/:/usr/share/:/var/lib/snapd/desktop.

If there is any information about my installation that I should provide, please tell me. Thank you.

I am using Ubuntu 20.04.2 LTS, with the awesome window manager, and gnome as my desktop.

The full output of running gnome-calculator is as follows:

(gnome-calculator:4038): Gtk-WARNING **: 06:23:42.942: Could not load a pixbuf from icon theme.
This may indicate that pixbuf loaders or the mime database could not be found.
**
Gtk:ERROR:../../../../gtk/gtkiconhelper.c:494:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /usr/share/icons/Yaru/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3)
Bail out! Gtk:ERROR:../../../../gtk/gtkiconhelper.c:494:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /usr/share/icons/Yaru/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3)
[1]    4038 abort (core dumped)  gnome-calculator

I recently started having this same problem, and none of these suggestions mentioned here worked for me. However, I now discovered the cause of my problem:

I had accidentally set the XDG_DATA_DIRS environment variable to point to a non-existent directory. Once I fixed this and ran the following, this Gtk problem went away ...

export XDG_DATA_DIRS=/path/to/a/real/and/accessible/directory

I also think that completely unsetting XDG_DATA_DIRS could fix the problem, as well.

I dont know what the error means tbh. But I just got the error from an Icon theme failure and I just moved the icon theme out of '/usr/share/icons' into another folder(somewhere like Downloads('~/Downloads/...' or Documents'~/Documents/...'). After that your icon theme should revert to the default and you will be able to use calculator. Hope this is relevant to your problem gl.

I was having the same error as well on my Arch machine. My firefox would crash if I tried open a file from my system in firefox. I found a site which describes a similar issue which fixed my problem: https://namespaceit.com/blog/could-not-find-mime-type-database-in-the-following-locations-usr-local-share-mime-packages-freedesktop.org.xml

Here's the Ubuntu equivalent of what I did:

sudo update-mime-database /usr/share/mime
sudo apt-get install shared-mime-info