Issue:
After upgrading Citrix XenDesktop 7.11 to 7.12 with Director on the same machine , Citrix Director stopped working and got stuck loading directly after login. After a bit of troubleshooting, seems that the issue lies here “System.ServiceModel.ServiceActivationException: The service ‘/Director/service.svc’ cannot be activated due to an exception during compilation.”
Solution:
We can solve this in one of two ways:
1- Open IIS and remove 8080 binding from “Default Web Site” and verify it is removed from “ Director ” .
2- Add multipleSiteBindingsEnabled=”true” /> to serviceHostingEnvironment in Director IIS directory web.config .
Salam 
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