Object identifier does not represent a valid object

[Nedim]

IIS Manager may display this error while starting a website: “The object identifier does not represent a valid object”

I saw this error for a SharePoint 2019 site hosted in Windows Server 2019 server

Solution

First, check the applicationHost.config file for corrupt configuration. If the same website is working on another server, compare the config files.

For the case I worked on, the website was missing folder path and application pool in the config. IIS Manager showed the path empty but there was DefaultAppPool for the application pool.

I copied site folders from another location and configured the path in IIS Manager. Then I selected the correct application pool for this website. It started working afterward.