Due to limitations with the current implementation of the ASP.NET Install Readiness Check during the installation/upgrade process, you may receive errors indicating that ASP.NET is not installed or is misconfigured.
Install Readiness Check states 'IIS script maps for ASP.NET 4.5.1 are missing or misconfigured'
Install Readiness Check states 'IIS script maps for ASP.NET are missing or misconfigured'
Current implementation of ASP.NET Install Readiness Check is code from a similar check that was written for IIS 6.0. It utilizes IIS6.0 metabase compatibility API and does not work at all if IIS7 was configured to use some features that were not supported in IIS6 (IPV6 for example). It was tested only with minimal default installation of IIS7.
Remove IPv6 addresses from the IP Address and Domain Restrictions IIS feature of the web server, web site or virtual directories.
Please see the following links from Microsoft for more information and how to add and/or remove these entries: