Has anyone else experienced this problem? I upgraded from sw06 sp 3.4 to sw06 sp4. with large assembly mode activated I try to open a large assembly drawing , the drawing won't open and the system hangs. If I open the large assembly model it opens fine. Set light weight to resolve and the drawing will open. In tools options if I turn off large assembly mode the drawing will open but I have to wait for everything to resolve. I rolled back to sp 3.4 and the large drawings open fine.