A new version of WordPress came out this weekend. This is primarily a Security Update so it is suggested for all users.
As normal some users are saying they are having problems updating.
For this reason you definitely want to do a full backup of all your files and database.
I strongly suggest that you delete your cache if you use wp supercache then disable caching before doing a backup of your files.
You should also keep your plugins off until wp 3.1.3 has installed.
This is the normal recommendation to turn your plugins off but most of us never do it. The reason to do this is so that when wordpress completes the install you can find all of the plugins with a new version compatible with the new version of WP or pick and choose which plugins to turn back on.
That way when wordpress relaunches it won’t hang on a plugin.
Complex themes can be just as bad during installs and you really should enable the default theme after disabling your plugins..
Yes this is the recommended method … we know no one does it that way.
I had my own problem updating that I am looking into now.
It seems my gallery for inserting images that you access on the Upload/Insert button above your post editor window shows 23 images but no images are displaying.
Sweet because I use these images every day..
Gees well If you know the fix I need pass a comment my way at the bottom of this page… if you have questions also ask.
If the install fails
I personally had the white screen of death with 3.1.2 and delayed its deployment on the rest of my sites after having to pull my hair out for 2 hours getting just one of my sites back up…. but 3.1.3 installed without problems.
If you need the older version
If you need to fix your install then follow the normal steps
disable plugins by renaming the directory
disable your theme by renaming your current theme unless you are using the wordpress default themes.
Even if you rename the theme folder you should still be able to login
Rollback is tougher and you really need your old database
If you did not make a backup then I would suggest that you reinstall 3.1.3 and hope it cures it.
Delete the wp-admin and wp-includes folders
delete your cache folders in your wordpress wp-content folder
do a manual install
goto website/wplocation/wp-admin/install.php OR update.php
however before you update manually
you need to backup everything you may have now
or join the irc chat on freenode #WordPress
and I will try to give you a hand