Just downloaded the latest CC 2017 version (fully updated) and as the project size reached 20 mb, it started to become super sluggish. Can't undo a keyframe delete and any other task basically. It freezes, goes to coma and sometimes totally crashes.
Is there a bug we are dealing with here? Any update coming to fix this?
What is in your project to make it get that size?
What OS? What hardware? Please double-check your exact AE version number and tell us what it is.
I haven't had the problem you're experiencing, but I can try to recreate it on my end if I have some more information.
Are you still facing this problem? If not, let us know how you solved it. If so, please let us know so we can assist you further.