I have a series of production websites that are currently running 4.6 with IIS 10. I can set the application pool identity to an internal service account. I can also set WCF services to that service account.

On my development and test servers, which are running net48 with IIS 10, the IIS will not allow me to set the application pool with the same service account although I can set WCF services to that same account and it works in all other contexts.

I also can’t set the application pool to my own Active Directory login, so it’s not the service account. In both cases (service and personal AD account), the IIS interface says the password is incorrect.

On the development server, I can modify the applicationHost.config file to paste the information in from an account that works on the same server, but that doesn’t work on my test server or any of my laptops running either Windows 10 or 11 with .NET Framework 4.8+ enabled or my test server.

When I do this on the IIS 10 with 4.8, IIS hangs and the application pool is shut down eventually.

I have tried to check the configurations (roles and features) to ensure the configuration of the system matches that of the working production server with net46, but it doesn’t seem to be a configuration issue as far as I can identify although I am sure it involves how IIS handles encryption using 4.8 vs 4.6.

I have verified that the LoadUserProfile flag is set to true.

The way my applications work, I need to be able to set the application pool identity to a service account.

Has anyone encountered with problem before, and, if so, is there a solution to this problem?