We have just updated WordPress to the latest version, 4.3.1, on sites.cardiff.ac.uk.
If you are using Chrome, you may notice a bug after you login to wp-admin. The left navigation may look broken, with items in the wrong places and text that moves around.
This is a bug in Chrome, rather than in WordPress, and should be fixed when the next version of Chrome is released.
If the bug is affecting you, and you have the necessary permissions, you can go to:
Enable the ‘disable slimming paint’ option and ensure that the option below, ‘enable slimming paint’ is NOT turned on.
Then restart your browser and the menu should work as expected.
If you cannot change your Chrome settings, then using another browser is an alternative work-around.