Another mysterious error. After installing IIS fresh on a new laptop, I was faced with this error message.
Failed to access IIS metabase.Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Web.Hosting.HostingEnvironmentException: Failed to access IIS metabase.
The process account used to run ASP.NET must have read access to the IIS metabase (e.g. IIS://servername/W3SVC). For information on modifying metabase permissions, please see http://support.microsoft.com/?kbid=267904.
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Anyway, its pretty easy to fix - run "aspnet_regiis.exe -i" from within the framework folder. The knowledge base link above talks about using the MetaACL tool to fix it but that didn't work for me, maybe it will for you and also using the -ga parameter didn't help me either.