WordPress 3.6 jQuery Error! Don’t panic, everything will be just fine in just a moment. You don’t have to worry about downgrading either.
If you are getting this error “blockUI requires jQuery v1.2.3 or later! You are using v1.10.2″ Let me explain what’s going on and how to fix the problem.
Basically your theme or plugins are using an older versions of jQuery and the developers need to update them.
We are going to get in to how to find where the problems lie in just a moment but for now here is a solution that made a quick fix for me.
I installed and activated jQuery Updater and it fixed the issue without any configuration. It actually has none so it made it really simple.
You can find the jQuery Updater download at WordPress.org for free here: http://wordpress.org/plugins/jquery-updater/
This solution worked for me but it may not work for you depending on what plugins or theme you have activated.
Lets get in to pin pointing the problem so we can actually fix it without a band-aid. Extra clutter in your plugin directory of your site is never good. Remember the more you make your visitors browser call for different files and make your server serve extra files the longer your web page takes to load.
When impatient visitors come to your site many will not wait past the 3 second mark before leaving your site.
Lets move forward and clean this issue up.
Lets start with your theme. Out of all the sites we had a problem with this was the biggest culprit.
If you have installed and activated jQuery Updater go ahead and deactivate it temporarily. Go to the front end of your site and you will see the error.
Now go to the admin panel and change your theme to Twenty Thirteen.
Navigate to the front end again to see if the error is gone, most likely it is.
If so change your theme back to the theme you normally use, activate jQuery Updater.
Now you can contact the developer of your theme to tell them about the issue. You might want to ask if they have an ETA on an update and if they can send you an email when it’s available.
If the error still occurs after the steps above, you need to deactivate plugins one by one until the error goes away. Once it does you have pin pointed the plugin causing the issue.
Then follow the same steps in contacting the developers about the issue/s.
I hoped this helped, if you need any help I’m a comment away.