You can’t always go off of only the browser version when troubleshooting problems in newer versions of Internet Explorer. We all know that unfortunately, different browser versions interpret the code for websites differently in some way or another. When troubleshooting end user problems the first thing I always try to find out is the name of the web browser and the version number being used by the user. That used to be all you needed to know for Internet Explorer until Microsoft added the option to view web sites in “Compatibility View” to recent versions of IE.
Compatibility View is a cool feature that allows users to view content designed for older web browsers in their newer version of Internet Explorer. What it basically does is render the web pages as if you were using an older browser. This works great if you’re having trouble viewing a site in a new browser that worked before you upgraded. However, “Compatibility View” can turn into “Incompatibility View” if a website was only designed for newer browsers and you turn that feature on. [more]
I’ve seen users accidently and unknowingly turn on the Compatibility View. After doing that they start having problems with a website that supports their browser version and used to work fine for them. It’s easy to do since the button is right next to the page refresh button in the address bar. I’ve also ran into users that have had to use the Compatibility View with other websites in the past so when they run into a problem on a different website they try turning it on and then forget to turn it off when it doesn’t fix their problem. IE remembers which sites you turned that view on for, so it automatically turns it on the next time you visit the site.
In my opinion the easiest way to view which version your browser is behaving as is to press F12 to open the developer tools window and look for the “Browser Mode” and “Document Mode” settings. You can click those options to change them.