If you from a site within a web application running with classic mode authentication try to create e.g. a team site and your mysite web application are running with claims authentication you will see the following error in your ULS Log.
System.UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED)), StackTrace:
at Microsoft.SharePoint.SPWeb.GetList(String strUrl)
at Microsoft.Office.Server.UserProfiles.SPSocialDataStore.OpenList(String name)
at Microsoft.Office.Server.UserProfiles.SPSocialDataStore.Initialize(SPWeb web, String url, Boolean bOwnDisposal)
at Microsoft.Office.Server.UserProfiles.FollowedContent.GetDataStore(SPS2SAppExecutionContext context)
at Microsoft.Office.Server.UserProfiles.FollowedContent.FollowItem(FollowedItem item, Boolean isInternal)
at Microsoft.Office.Server.UserProfiles.FollowedContent.Follow(Uri url, FollowedItemData data)
at Microsoft.SharePoint.Portal.SiteFeedFeatureReceiver.AutoFollowWeb(SPWeb web)
at Microsoft.SharePoint.Portal.SiteFeedFeatureReceiver.FeatureActivated(SPFeatureReceiverProperties properties)
at Microsoft.SharePoint.SPFeature.DoActivationCallout(Boolean fActivate, Boolean fForce)
at Microsoft.SharePoint.SPFeature.Activate(SPSite siteParent, SPWeb webParent, SPFeaturePropertyCollection props, SPFeatureActivateFlags activateFlags, Boolean fForce)
at Microsoft.SharePoint.SPFeatureCollection.AddInternal(SPFeatureDefinition featdef, Version version, SPFeaturePropertyCollection properties, SPFeatureActivateFlags activateFlags, Boolean force, Boolean fMarkOnly)
at Microsoft.SharePoint.SPFeatureCollection.AddInternalWithName(Guid featureId, Int32 compatibilityLevel, String featureName, Version version, SPFeaturePropertyCollection properties, SPFeatureActivateFlags activateFlags, Boolean force, Boolean fMarkOnly, Boolean fIgnoreMissing, SPFeatureDefinitionScope featdefScope)
at Microsoft.SharePoint.SPFeatureCollection.AddInternal(Guid featureId, Version version, SPFeaturePropertyCollection properties, Boolean force, Boolean fMarkOnly, SPFeatureDefinitionScope featdefScope)
at Microsoft.SharePoint.SPFeatureCollection.Add(Guid featureId, Boolean force)
at Microsoft.SharePoint.SPWeb.ApplyWebTemplate(SPWebTemplate webTemplate, Page page, SPFeatureDependencyErrorBehavior featureDependencyErrorBehavior, ICollection`1& featureDependencyErrors)
at Microsoft.SharePoint.ApplicationPages.TemplatePickerUtil.ApplyWebTemplateAndRedirect(SPWeb Web, String strWebTemplate, Nullable`1 bSharedNav, Boolean bOnTopNav, Boolean bOnQuickLaunch, Page page, Boolean bDeleteOnError, SPFeatureDependencyErrorBehavior featureDependencyErrorBehavior, ICollection`1& featureDependencyErrors)
at Microsoft.SharePoint.ApplicationPages.NewSubwebPage.BtnCreateSubweb_Click(Object sender, EventArgs e)
at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
at System.Web.HttpApplication.PipelineStepManager.ResumeSteps(Exception error)
at System.Web.HttpApplication.BeginProcessRequestNotification(HttpContext context, AsyncCallback cb)
at System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context)
at System.Web.Hosting.PipelineRuntime.ProcessRequestNotificationHelper(IntPtr rootedObjectsPointer, IntPtr nativeRequestContext, IntPtr moduleData, Int32 flags)
at System.Web.Hosting.PipelineRuntime.ProcessRequestNotification(IntPtr rootedObjectsPointer, IntPtr nativeRequestContext, IntPtr moduleData, Int32 flags)
at System.Web.Hosting.UnsafeIISMethods.MgdIndicateCompletion(IntPtr pHandler, RequestNotificationStatus& notificationStatus)
at System.Web.Hosting.UnsafeIISMethods.MgdIndicateCompletion(IntPtr pHandler, RequestNotificationStatus& notificationStatus)
at System.Web.Hosting.PipelineRuntime.ProcessRequestNotificationHelper(IntPtr rootedObjectsPointer, IntPtr nativeRequestContext, IntPtr moduleData, Int32 flags)
at System.Web.Hosting.PipelineRuntime.ProcessRequestNotification(IntPtr rootedObjectsPointer, IntPtr nativeRequestContext, IntPtr moduleData, Int32 flags)
The reason is that the team website try to activate the ‘SiteFeed’ Feature (ID: ’15a572c6-e545-4d32-897a-bab6f5846e18′), which on your behalf will subscribe you to the newsfeed of the website. But because of the different authentications modes, it will fail to activate and the site creation will fail.
The solution is to use the same authentication on both applications.
Or alternatively you can remove the Service Application Association to the User Profile Service Application from the web application running classic authentication, then the feature will not try to subscribe you to the news feed and site creation will succeed.