I know this is an old thread but I ended up having to do two things
1) manually edit the web.config by adding:
<system.web>
<compilation debug="false" targetFramework="4.5"/>
</system.web>
2) Edit the advanced settings of your Application Pool
Enable 32-Bit Applications=True
Uninstall (stop iis first) if it is already installed (mine was) and install again fresh.