I have upgraded from cms 6 to 7.19.2. In the visitor group episerver page the X-UA-Compatible is set to IE=9. And it is NOT working in IE=9, though it's in Edge mode. How can i change that?
One of the fast and hacky way would be to temporary update `VisitorGroup.Master` file inside `modules\_protected\CMS\EPiServer.Cms.Shell.UI.zip\Views\Shared`. But remember that any package upgrade will reset that.
Another way that we did was to intercept outgoing html and change compatibility level on the fly (as we have some issues with iframe height on some of the browsers in Admin UI). Don't have code at hand yet to share.
As far as I remember CMS packages have been converted to protected modules starting from 7.6 release. You should have those files there. Are you adding your Cms UI folders to the website through virtual paths in web.config?