Description

A default installation of a Content Delivery (CD) instance uses only a Web database. However, some site definitions might refer to the Core database:

<site name="shell" .....database="core" ....
<site name="login" .... database="core"....
<site name="modules_shell" ..... database="core" 

The following error message can be found in the CD log records:

ERROR Exception while handling event Sitecore.Data.Eventing.Remote.SavedItemRemoteEvent
Exception: System.InvalidOperationException
Message: Could not find configuration node: databases/database[@id='core']
Source: Sitecore.Kernel
   at Sitecore.Configuration.DefaultFactory.GetConfigNode(String xpath, Boolean assert)
   at Sitecore.Configuration.DefaultFactory.CreateObject(String configPath, String[] parameters, Boolean assert)
   at Sitecore.Configuration.DefaultFactory.GetDatabase(String name, Boolean assert)
   at Sitecore.Configuration.DefaultFactory.GetDatabase(String name)
   at Sitecore.Caching.ItemCache.FindAvailableKeys(SiteInfo site, ID itemId)
   at Sitecore.Caching.ItemCache.RemoveItemFromFilterCaches(ID itemId)
   at Sitecore.Caching.ItemCache.RemoveItem(ID itemId)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at Sitecore.Eventing.Subscription`1.Invoke(Object instance, EventContext context)
   at Sitecore.Eventing.EventProvider.RaiseEvent(Object event, Type eventType, EventContext context

Solution

To resolve the issue, you can comment out the shell, login, and modules_shell site nodes, as shown in the following example:

• For Sitecore XP 9.1 Initial release and 9.2 Initial release, in \App_Config\Sitecore.config file.
• For Sitecore XP 9.3 Initial release and higher, in \App_Config\Sitecore\CMS.Core\Sitecore.Sites.config file.

...
<!--  <site name="shell" virtualFolder="/sitecore/shell" physicalFolder="/sitecore/shell" rootPath="/sitecore/content" startItem="/home"  language="en" contentLanguage="en" database="core" domain="sitecore" loginPage="/sitecore/login" content="$(defaultContentDatabaseName)" contentStartItem="/Home" enableWorkflow="true" enableTracking="false" analyticsDefinitions="content" xmlControlPage="/sitecore/shell/default.aspx" browserTitle="Sitecore" htmlCacheSize="10MB" registryCacheSize="15MB" viewStateCacheSize="1MB" xslCacheSize="25MB" disableBrowserCaching="true" enableItemLanguageFallback="false" enableFieldLanguageFallback="false" /> -->
...
<!-- 
<site name="login" virtualFolder="/sitecore/login" physicalFolder="/sitecore/login" enableTracking="false" database="core" domain="sitecore" disableXmlControls="true" language="en" /> -->
 ...
<!--    <site name="modules_shell" virtualFolder="/sitecore modules/shell" physicalFolder="/sitecore modules/shell" rootPath="/sitecore/content" startItem="/home" language="en" database="core" domain="sitecore" content="$(defaultContentDatabaseName)" enableTracking="false" enableWorkflow="true" /> -->
...