When you encounter a similar issue, the following action may help solve the problem:
Call:
aspnet_regiis.exe /iru
through the command prompt. You can find it in the folder:
* %windir%\Microsoft.NET\Framework\v4.0.30319
* %windir%\Microsoft.NET\Framework64\v4.0.30319 (64-bit machine)
Additional info can be found under the links below:
IIS.NET blogs
DevOneNode
-rm-