Description

When the value of the requireSSL attribute in the Web.config file is set to "true":

<authentication mode="Forms">
 <forms loginUrl="member_login.aspx" cookieless="UseCookies" requireSSL="true" path="/MyApplication" />
</authentication>

the pre-emptive screenshot generation does not work properly and can cause various issues. For example, the package generation can fail, with the following error in the log:

Message: The application is configured to issue secure cookies. These cookies require the browser to issue the request over SSL (https protocol). However, the current request is not over SSL.
 Source: System.Web
   at System.Web.Security.FormsAuthentication.SetAuthCookie(String userName, Boolean createPersistentCookie, String strCookiePath)
   at Sitecore.Security.Authentication.FormsAuthenticationProvider.Login(User user)
   at Sitecore.ContentTesting.Events.GenerateScreenshot.PopulateCookiesForNewSession(List`1 cookies)
   at Sitecore.ContentTesting.Events.GenerateScreenshot.StartRun(Item item, ItemChanges changes)
   at Sitecore.ContentTesting.Events.GenerateScreenshot.OnItemSaved(Object sender, EventArgs args)
   at Sitecore.Events.Event.EventSubscribers.RaiseEvent(String eventName, Object[] parameters, EventResult result)
   at Sitecore.Events.Event.RaiseEvent(String eventName, Object[] parameters)
   at Sitecore.Events.Event.RaiseItemSaved(Object sender, ItemSavedEventArgs args)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at Sitecore.Data.Engines.EngineCommand`2.RaiseEvent[TArgs](EventHandler`1 handlers, Func`2 argsCreator)
   at Sitecore.Data.Engines.EngineCommand`2.Execute()
   at Sitecore.Data.Engines.DataEngine.SaveItem(Item item)
   at Sitecore.Data.Managers.ItemProvider.SaveItem(Item item)
   at Sitecore.Data.Managers.PipelineBasedItemProvider.ExecuteAndReturnResult[TArgs,TResult](String pipelineName, String pipelineDomain,Func`1pipelineArgsCreator, Func`1 fallbackResult)
   at Sitecore.Data.Managers.PipelineBasedItemProvider.SaveItem(Item item)
   at Sitecore.Data.Items.ItemEditing.AcceptChanges(Boolean updateStatistics, Boolean silent)
   at Sitecore.Install.Items.ItemInstaller.VersionInstaller.InstallVersion(Item version)
   at Sitecore.Install.Items.ItemInstaller.VersionInstaller.PasteVersion(XmlNode versionXml, Item target, VersionInstallMode mode, IProcessingContext context, Boolean removeOtherVersions)
   at Sitecore.Install.Items.ItemInstaller.InstallEntry(PackageEntry entry)

Solution

To resolve the issue, disable the pre-emptive screenshot generation.

Sitecore XP 8.0 Initial Release – 8.1 Update-2:

Open the \App_Config\Include\Content Testing\Sitecore.ContentTesting.config file and comment out the following lines:

<event name="item:saved">
  <handler type="Sitecore.ContentTesting.Events.GenerateScreenshot, Sitecore.ContentTesting" method="OnItemSaved">
    <excludeFields hint="list:ExcludeFieldFromComparison">
      <created>__created</created>
      <createdby>__created by</createdby>
      <updated>__updated</updated>
      <updatedby>__updated by</updatedby>
      <revision>__revision</revision>
      <sortorder>__sortorder</sortorder>
      <validfrom>__valid from</validfrom>
      <workflow>__workflow</workflow>
      <workflowstate>__workflow state</workflowstate>
      <lock>__lock</lock>
      <pageleveltestsetdefinition>__Page Level Test Set Definition</pageleveltestsetdefinition>
    </excludeFields>
  </handler>
</event>

<event name="item:saved:remote">
  <handler type="Sitecore.ContentTesting.Events.GenerateScreenshot, Sitecore.ContentTesting" method="OnRemoteItemSaved">
    <excludeFields hint="list:ExcludeFieldFromComparison">
      <created>__created</created>
      <createdby>__created by</createdby>
      <updated>__updated</updated>
      <updatedby>__updated by</updatedby>
      <revision>__revision</revision>
      <sortorder>__sortorder</sortorder>
      <validfrom>__valid from</validfrom>
      <workflow>__workflow</workflow>
      <workflowstate>__workflow state</workflowstate>
      <lock>__lock</lock>
      <pageleveltestsetdefinition>__Page Level Test Set Definition</pageleveltestsetdefinition>
    </excludeFields>
  </handler>
</event>

Sitecore XP 8.1 Update-3 and later:

Disable the \App_Config\Include\Content Testing\Sitecore.ContentTesting.PreemptiveScreenshot.config file.