Proper User Acceptance Testing
Check Everything Before You Publish
Before you make your website live again, it is vital to check all of your modules, widgets, custom codes, and everything else that could have possibly been affected by the upgrade. You may need to reset your settings because they may have changed when you upgraded. Some of the modules and widgets that you use may be outdated and not supported by the new version you upgraded to, which could mean parts of your website no longer work like they used to or deliver error codes. You upgraded your CMS to make your website better, don’t ruin it by being anything less than thorough.