Post-upgrade from 12.04 LTS to 14.04 LTS, GTK cannot open .png files

[RecceDG]

I have had multiple problems with an upgrade from 12.04 LTS to 14.04 LTS.

This specific issue involves multiple errors from GTK and other glib applications not being able to process .png files.

The crash files refer to

GError: Unrecognized image file format.
GError: Couldn't recognize the image file format for file

etc. All files referred to are .png

Running gtk applications such as gimp produces a long list or warnings of the nature:

Gtk-WARNING **: Error loading theme icon 'edit-cut' for stock: Unrecognized image file format

The images load fine in gimp as images. As icons, nothing loads.

I have reinstalled glib and libpng to no effect.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1360522/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[RecceDG (reccedg)]

Re-installing shared-mime-info and running the update-mime-database command fixed this.

Bug can be closed, I guess.

Note that the update also trashed pam (I had to reinstall that and run the pam update script). Grub2 was borked and required a patch and a workaround. Firefox is now randomly crashing, and Civ V now segfaults on launch.

It has been a long couple of days and everything is still not fixed.