If you still have web in your URL, then you’re rewrite rules are not correct - the root of the installation shouldn’t be web serviceable.
Have you read the excellent guide written by someone in the community: XIBO step by step Installation IIS 8.5 on WINDOWS SERVER 2012 - #12 by Gio?
It is also possible you’re getting this: "The length of the URL for this request exceeds the configured maxUrlLength value"