You may need to give access to the IIS_IUSRS group or IUSR user for the application folder. Please verify also if you have IIS URL Rewrite module installed - this is needed because of Angular/HTML 5 routing.
According to the IIS deployment documentation this error could occur if .NET Core support isn’t installed on that server:
Confirm that you have enabled the proper role. See IIS Configuration.
Check Programs & Features and confirm that the Microsoft ASP.NET Core Module has been installed. If the Microsoft ASP.NET Core Module is not present in the list of installed programs, install the module. See Install the .NET Core Windows Server Hosting bundle.
Make sure that the Application Pool > Process Model > Identity is set to ApplicationPoolIdentity or your custom identity has the correct permissions to access the application’s deployment folder.
Finally invalid web.config could also cause that. Could you paste here the web.config from the %SYSTEMDRIVE%\inetpub\wwwroot[APPLICATION_NAME]\ directory (the one Radzen created)?