UmbracoContext.InPreviewMode always false, Umbraco.Context.Security.CurrentUser always null

[dhymik]

After I install UmbracoIdentity into a clean Umbraco 8 installation, UmbracoContext.InPreviewMode always returns false. The reason is that Umbraco.Context.Security.CurrentUser always returns null with UmbracoIdentity installed.

Can I do something to prevent this from happening?

[dvdvliet]

I ran into exactly the same issue and took me a while to figure out.

This is fixed by changing the example of the UmbracoIdentityOwinStartup code a bit.

Remove the line

base.ConfigureUmbracoAuthentication(app);

instead add these lines (and add an extra using Umbraco.Web.Security;)

app
     .UseUmbracoBackOfficeCookieAuthentication(UmbracoContextAccessor, RuntimeState, Services.UserService,
         GlobalSettings, UmbracoSettings.Security, PipelineStage.Authenticate)
     .UseUmbracoBackOfficeExternalCookieAuthentication(UmbracoContextAccessor, RuntimeState, GlobalSettings,
         PipelineStage.Authenticate);

Now place your custom code and authentication configurations.

Finally at the end add these lines of code

// this must come after all authentication so should be moved within ConfigureMiddleware
app.UseUmbracoPreviewAuthentication(UmbracoContextAccessor, RuntimeState, GlobalSettings, UmbracoSettings.Security, PipelineStage.Authorize);