I have an existing ASP.NET webforms application written in VB.NET and running on .NET 4.8 which is perfectly running on the production server since 2022. At that time prod server was Windows Server 2016.
Recently, I enhanced the application and deployed to the Dev server (Windows Server 2016) and Staging server (Windows Server 2019) for testing. Everything is working fine.
Finally, the application deployed to the prod server with new code and modified prod config file. Last year, the prod server was upgraded from 2016 to 2019. When I ran the application from prod I am now getting a http 500 error.
As per the deployment teams statement there is a correct permission on the site folder because it is existing application not new application.
Detailed error info:
HTTP Error 500.19 -Internal Server Error The requested page cannot be accessed because the related configuration data for the page is invalid
Module : IIS Web Core
Notification: BeginRequestError Code : 0x80070003
Config error : Cannot read configuration file
Config file : \?<file path>\web.config
Request Url : https://localhost:443/prj/menu.aspx
Physical path : \menu.aspx
IIS 10.0
I could not find the root cause. I searched in google but did not find solution. I am totally stuck.
Any kind of hints or idea is more appreciated.