I tried making a map of an island. It was all woking really smooth after the newest update, but then I wanted to shorten my work by copy-pasting trees, houses and other pieces of terrain and architecture. Then Animate CC started to create massive lags and even selecting clusters of trees causes it to lag and get into "no respond" state for a while. Anybody knows how to fix it?
you can try closing and restarting animate to see if the problem resolves (at least, for a while).
if it does not, you're probably taxing your gpu and/or ram.
There is a finite point in Animate whereby if you add too much onto the Stage it will cause it to slow down and lag which is governed by your graphics card and your memory. It sounds like you hit that point. There are a few things you can do... Go to View/Preview Mode and turn the view down to Fast and that may work. If it doesn't Outlines might help.