Increase the preferred memory size of the Pro Tools Application.If this does not solve the problem, take note of the progress bar that's on the screen before this error message appears; this gives you a good hint where to search for the problem. For instance, when Pro Tools aborts the Save Session Copy In process when it says "copying Plug-In Settings", some of your Plug-In Settings files may have been damaged (by a power failure, for instance). In such a case, Try copying the session without copying the Fade files and the Session and Root Plug-In Settings folders.