Name cannot begin with the ' ' character, hexadecimal value 0x0A.

 Error:

Server Error in '/' Application.

Name cannot begin with the '

' character, hexadecimal value 0x0A. Line 41, position 81.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Xml.XmlException: Name cannot begin with the '

' character, hexadecimal value 0x0A. Line 41, position 81.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[XmlException: Name cannot begin with the '

' character, hexadecimal value 0x0A. Line 41, position 81.]

   System.Xml.XmlTextReaderImpl.Throw(Exception e) +91

   System.Xml.XmlTextReaderImpl.ParseQName(Boolean isQName, Int32 startOffset, Int32& colonPos) +288

   System.Xml.XmlTextReaderImpl.ParseElement() +258

   System.Xml.XmlTextReaderImpl.ParseElementContent() +552

   System.Xml.XmlLoader.LoadNode(Boolean skipOverWhitespace) +1025

   System.Xml.XmlLoader.LoadDocSequence(XmlDocument parentDoc) +67

   System.Xml.XmlDocument.Load(XmlReader reader) +137

   Sitecore.Configuration.ConfigPatcher.GetXmlElement(XmlReader reader, String sourceName) +112

   Sitecore.Configuration.ConfigPatcher.ApplyPatch(TextReader patch, String sourceName) +99

   Sitecore.Configuration.ConfigPatcher.ApplyPatch(String filename) +92

   Sitecore.Configuration.ConfigReader.LoadIncludeFiles(ConfigPatcher patcher, IEnumerable`1 files) +150

[ConfigurationException: An error occurred during applying the patch file: c:\inetpub\wwwroot\sc1011devsc.dev.local\App_Config\Sitecore\Services.GraphQL\Sitecore.Services.GraphQL.Serialization.config]

   Sitecore.Configuration.ConfigReader.LoadIncludeFiles(ConfigPatcher patcher, IEnumerable`1 files) +362

   Sitecore.Configuration.ConfigReader.DoGetConfiguration() +402

   Sitecore.Configuration.ConfigReader.GetConfiguration() +236

   Sitecore.DependencyInjection.ServiceLocator.ConfigureServiceProvider() +13

   Sitecore.DependencyInjection.ServiceLocator.get_ServiceProvider() +513

   Sitecore.DependencyInjection.SitecorePerRequestScopeModule..ctor() +13

[TargetInvocationException: Exception has been thrown by the target of an invocation.]

   System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck) +0

   System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark) +142

   System.Activator.CreateInstance(Type type, Boolean nonPublic) +107

   System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, StackCrawlMark& stackMark) +1476

   System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) +186

   System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture) +28

   System.Web.HttpRuntime.CreateNonPublicInstance(Type type, Object[] args) +80

   System.Web.HttpApplication.BuildIntegratedModuleCollection(List`1 moduleList) +234

   System.Web.HttpApplication.GetModuleCollection(IntPtr appContext) +1153

   System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +139

   System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +168

   System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +277

   System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +369

[HttpException (0x80004005): Exception has been thrown by the target of an invocation.]

   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +532

   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +111

   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +724

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4330.0

Cause:

The config file, this case, Sitecore.Services.GraphQL.Serialization.config had an extra, unwanted < sign that I unintentionally added when I was modifying some settings in the config file. Got rid of of it and the error was gone.