Here's another issue we saw a couple times during the App-V 4.5 beta. It's probably something that would be fairly uncommon but in case you're having trouble restarting a Microsoft Application Virtualization Streaming Server after it's been stopped then this would be something to look at:
Issue: After stopping a Microsoft Application Virtualization Streaming Server, an attempted restart of the service may fail with a 268477060 error.
Cause: If an App-V client is still running a streamed application from the server it cannot be fully stopped. This is a known issue and is expected behavior because the process SGLWSVR.EXE will keep running if a streamed application is still in use by a client. When the Streaming Server service then tries to restart it will be unable to do so and display the error code 268477060.
Resolution: If a Microsoft Application Virtualization Streaming Server has already been stopped and unable to restart, use Task Manager to kill the SGLWSVR.EXE process. To prevent the situation from occurring in the future, prior to stopping the Streaming Server have the clients close any virtual applications that are running.
J.C. Hornbeck | Manageability Knowledge Engineer