on occassion when a Blu-ray burn doesn't work or even when it has worked but Encore closes prematurely, I sometimes have to delete the folder called: AuthorScriptHDMVSessions. It gets made in the project sub-folder anytime you start a Build Disk and if it gets corrupted it will cause what appear to be nonsense error messages.
Always good to check. And once upon a time, it was a frequent problem. But as of CS5.5 or CS6, they changed so this folder was automatically deleted.
