NullReferenceException when publishing content during epi initialization

[MikolajDlus]

When trying to update (publishing) content during epi initialization (f.e. with Forte Migrations) system throws NullReferenceException while checking for edit access rights. As a workaround we have to disable automatic redirects before saving content and reenable it after.

Stacktrace:

System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Web.Security.UrlAuthorizationModule.CheckUrlAccessForPrincipal(String virtualPath, IPrincipal user, String verb)
   at EPiServer.Security.Internal.PathAccessChecker.HasPathAccess(String path, IPrincipal principal)
   at EPiServer.Security.Internal.PathAccessChecker.HasEditAccess(IPrincipal principal)
   at EPiServer.Web.Internal.DefaultDisplayChannelService.<>c.<.ctor>b__3_0(IPrincipal p)
   at EPiServer.Web.Internal.DefaultDisplayChannelService.GetActiveChannels(HttpContextBase context)
   at EPiServer.Web.Internal.TemplateResolverImplementation.ResolveCore(HttpContextBase httpContext, ContentType contentType, Type itemType, Object itemToRender, TemplateTypeCategories category, String tag)
   at EPiServer.Web.TemplateResolver.Resolve(HttpContextBase httpContext, Object itemToRender, TemplateTypeCategories templateTypeCategory, ContextMode contextMode)
   at EPiServer.Web.TemplateResolver.HasTemplate(IContentData contentData, TemplateTypeCategories templateTypeCategory, ContextMode contextMode)
   at EPiServer.Web.Routing.Internal.DefaultUrlResolver.GetVirtualPath(ContentReference contentLink, String language, VirtualPathArguments arguments)
   at Forte.EpiserverRedirects.System.SystemRedirectsEventsModule.GetContentUrl(ContentReference contentReference, String language, Boolean validateTemplate)
   at Forte.EpiserverRedirects.System.SystemRedirectsEventsModule.PublishedContentHandler(Object sender, ContentEventArgs e)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at EPiServer.Core.Internal.DefaultContentEvents.RaiseContentEvent(String key, ContentEventArgs eventArgs)
   at EPiServer.Core.Internal.DefaultContentRepository.RaisePostSaveEvents(SaveContentEventArgs eventArgs, StatusTransition transition, Boolean isNew, Boolean isNewLanguageBranch)
   at EPiServer.Core.Internal.DefaultContentRepository.Save(IContent content, SaveAction action, AccessLevel access)
   at Farmasiet.CMS.Migrations.InitializeLowStockTresholdSetting.ExecuteAsync() in E:\Dev\Repos\Farmasiet\Farmasiet.CMS\Migrations\052_InitializeLowStockTresholdSetting.cs:line 31
   at Forte.Migrations.EPiServer.RunAsMigrationDecorator.Decorator.<ExecuteAsync>d__3.MoveNext()```