Before you upgrade , go to WP-Admin for your blog on WordPress and to the Tools which is the spanner icon 3rd up from the bottom. Select Export and download your xml file. That preserves your blog as it is. Do that in any case because it is the back up for your blog. All my upgrades so far have gone well except one so the last one is not going to happen yet. The one which has been difficult has been glitchy and odd. Every other one has been straight forward. I am now reconstructing the tetchy blog and am just about here. If I click on customisations it is becoming jumpy and silly. Patience is a virtue. I am getting there , though. Some blog templates put everything at the bottom because it means they run faster on a tablet or smartphone. Classic mobile you-do-not-need-to know thinking. Mobile technology strips things down and so you are not getting the full experience necessarily of a website as you would on a computer. If you know that, you know what you don’t easily have access to. If you do not know that then we are back to the WYSIATI thinking and it can be limiting. I am trying to build blogs which have good information and then good links out but I also want them to run efficiently. Getting the new templates has really improved mobile performance and that was my main aim. On a tablet this blog runs without the sidebars and all of that information is right at the bottom after you have scrolled down. On my phone it is more like a burner feed and just shows the text. This blog , though , is now running very fast and effectively on mobile devices and I am now happy the new look. Basically it takes a little bit of time and tinkering.