Hi . Im i have some problem when open my file ( my file around 200mb-1000mb ) . too slow , about 2-10 minute . And when i copy some model form old project to new project , it take 5-10 minute .
Window menu>Model Info>Statistics>Purge Unused.
Get rid of 3D entourage components (trees, cars, people…) downloaded from the 3D Warehouse or replace them with simplified versions.