If your get the following App-V client error when refreshing your apps from the App-V Client Console: The Application Virtualization Client could not update publishing information from the server App-V Server. The server will not allow a connection without valid NTLM credentials. Report the following error code to your System Administrator. Error code: 4615186-1690900A-00002002 And [...]

An excellent Hyper-V gotchas paper has been published here by Tony Soper and Stephan Schwarz on the Microsoft TechNet Wiki. It is a gold mine for understanding and troubleshooting Hyper-V.