It would appear the CrowdStrike issue that plagued PC's and server's worldwide may cause some SSRS instances to stop being able to be started on a CHE Tier-1 for D365FO.
The following error below may be present within event viewer when trying to start the SSRS service. This issue is due to the corruption of a SSRS web.config file
Application: RSHostingService.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.Xml.XmlException
at System.Xml.XmlTextReaderImpl.Throw(System.Exception)
at System.Xml.XmlTextReaderImpl.ThrowInvalidChar(Char[], Int32, Int32)
at System.Xml.XmlTextReaderImpl.ParseRootLevelWhitespace()
at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
at System.Xml.XmlReader.MoveToContent()
at System.Xml.Linq.XElement.Load(System.Xml.XmlReader, System.Xml.Linq.LoadOptions)
at System.Xml.Linq.XElement.Load(System.String, System.Xml.Linq.LoadOptions)
at Microsoft.BIServer.Configuration.ConfigReader..ctor(System.String)
at Microsoft.BIServer.BIService.ServiceConfig..ctor(System.String)
at Microsoft.BIServer.BIService.BIService.SetNewConfigFilePathIfExists(System.String)
at Microsoft.BIServer.BIService.BIService..ctor()
at Microsoft.BIServer.BIService.Program.Main()
Faulting application name: RSHostingService.exe, version: 15.0.1102.1084, time stamp: 0x64b6b433
Faulting module name: KERNELBASE.dll, version: 10.0.20348.2400, time stamp: 0x784b07c7
Exception code: 0xe0434352
Fault offset: 0x000000000003f19c
Faulting process id: 0x2824
Faulting application start time: 0x01dae1f335c6e225
Faulting application path: C:\Program Files\Microsoft SQL Server Reporting Services\SSRS\RSHostingService\RSHostingService.exe
Faulting module path: C:\Windows\System32\KERNELBASE.dll
In order to fix the issue the following needs to occur
1.) Go to C:\Program Files\Microsoft SQL Server Reporting Services\SSRS\ReportServer2.) Rename web.config to web.config.old or web.config.bak3.) Copy new web.config to C:\Program Files\Microsoft SQL Server Reporting Services\SSRS\ReportServer4.) Open Services.msc5.) Start SQL Server Reporting Services
You can download the needed default web.config here
You may also run into the following files needing to be replaced as well
C:\Program Files\Microsoft SQL Server Reporting Services\SSRS\ReportServer\rssrvpolicy.config
C:\Program Files\Microsoft SQL Server Reporting Services\SSRS\Portal\RSPortal.exe.config
You can tell if it needs to be replaced or not by simply opening the text file in note pad. If its blank its needs replaced if you can see text you are fine.