Ok, I've found a solution, but have no idea why it works...
public class CustomizedRenderingInitialization : IInitializableModule
public void Initialize(InitializationEngine context)
ViewEngines.Engines.Insert(0, new RazorViewEngine());
Does this mean that EPiServer doesn't initialize the RazorViewEngine by default?
Before updating to EPiServer Edit UI 2.0.79 it worked without this initialization.
This would have been my suggested solution. The reason this is necessary after the update is because we've added a new route specifically for a new ContentArea template. This new route is evaluated before the default view engine. I will create a bug to address the route order since there is no reason why the default route shouldn't be first. But in the mean time I suggest using the fix that you have currently.
As an aside: this new template is what adds the block personalization support. If you are overriding the ContentArea template please be aware that you will break the personalization support for blocks.
After upgrading AddOn store platform and/or Edit UI from AddOn store the convention to look for templates in DisplayTemplates seem broken for ContentAreas. When trying to render a ContentArea by using Html.PropertyFor the only template being used is the one in [CMS_Installation_Directory]\Application\Util\Views\Shared\DisplayTemplates, not the one I created (~/Views/Shared/DisplayTemplates/ContentArea.cshtml).
Placing a file named String.cshtml in ~/Views/Shared/DisplayTemplates let me render the string however I want using Html.PropertyFor(x => x.MyString)
Any ideas what might be wrong?