Exchange Server Install Errors - aaqibwani/M365 GitHub Wiki

You receive the following error when installing or upgrading an Exchange Server:

Error: The following error was generated when "$error.Clear(); ."$RoleInstallPath\Scripts\ConfigureCafeResponseHeaders.ps1"; CreateCustomHeadersNodeForBackend 'autodiscover' CreateCustomHeadersNodeForBackend 'ecp' CreateCustomHeadersNodeForBackend 'ews'
CreateCustomHeadersNodeForBackend 'oab' CreateCustomHeadersNodeForBackend 'owa' CreateCustomHeadersNodeForBackend 'powershell' CreateCustomHeadersNodeForBackend 'pushnotifications' CreateCustomHeadersNodeForBackend 'rpcproxy' CreateCustomHeadersNodeForBackend 'sync' CreateCustomHeadersNodeForBackend 'mapi\emsmdb' CreateCustomHeadersNodeForBackend 'mapi\nspi' " was run: "System.Management.Automation.MethodInvocationException: Exception calling "Load" with "1" argument(s): "Root element is missing." ---> System.Xml.XmlException: Root element is missing. at System.Xml.XmlTextReaderImpl.Throw(Exception e) at System.Xml.XmlTextReaderImpl.ParseDocumentContent() at System.Xml.XmlLoader.Load(XmlDocument doc, XmlReader reader, Boolean preserveWhitespace) at System.Xml.XmlDocument.Load(XmlReader reader) at System.Xml.XmlDocument.Load(String filename) at Load(Object , Object[] ) at System.Management.Automation.DotNetAdapter.AuxiliaryMethodInvoke(Object target, Object[] arguments, MethodInformation methodInformation, Object[] originalArguments) --- End of inner exception stack trace --- at System.Management.Automation.DotNetAdapter.AuxiliaryMethodInvoke(Object target, Object[] arguments, MethodInformation methodInformation, Object[] originalArguments) at System.Management.Automation.DotNetAdapter.MethodInvokeDotNet(String methodName, Object target, MethodInformation[] methodInformation, PSMethodInvocationConstraints invocationConstraints, Object[] arguments) at System.Management.Automation.DotNetAdapter.MethodInvoke(PSMethod method, PSMethodInvocationConstraints invocationConstraints, Object[] arguments) at System.Management.Automation.Adapter.BaseMethodInvoke(PSMethod method, PSMethodInvocationConstraints invocationConstraints, Object[] arguments) at System.Management.Automation.Interpreter.DynamicInstruction`3.Run(InterpretedFrame frame) at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)".

Cause: Corrupted/empty Web.config file

Solution: Copy Web.config file(s) from a working server on the same CU or from the installation path under the setup folder (example: F:\Setup\ServerRoles). If you received an error while installing the Client Access Role, you can go to %ExchangeInstallPath%\ClientAccess\ or :\Setup\ServerRoles and copy the web.config files from each of the directories Autodiscover, OWA, ECP etc., and paste it into the affected servers install path.