3 Upgrade Universal Analytics
Upgrade Universal Analytics as soon as possible. You have two options. You might still be using the old Google Analytics tag (ga.js) or not have the new Google Analytics tag (analytics.js) firing from all, or any, of your pages.
If you still have the old tag on your site (Google Tag Assistant will tell) you can find a guide on how to upgrade here. Make sure that you have only one version of the tag live at the same time on your website. Upgrading is fairly simple, unless you have set up a lot of custom events in the old version. Keeping those exactly the same will require some work. If you are not using them, just ignore them in the upgrade and they will not show up in the new setup.
If only a small part of your website is currently tagged up with the Google Analytics you will need to deploy the new Google Analytics tag on the pages that are missing the tag. If you have not installed a tag management solution yet, we would recommend using Google Tag Manager (GTM) to deploy all of the new tags.
Why upgrade it is working fine now?
Once you upgrade to Universal Analytics, you will have several new options. You will be able to capture custom dimensions quiet easily, from within the Google Analytics interface. A lot of the configuration options you can then control from your account admin page. And last but not least, enhanced ecommerce and the measurement protocol allow you to get a lot more sophisticated about what you can measure.
Sooner or later, Google will pull the plug on the old classical analytics tag. Make sure you have upgraded when that happens.