This has been happening on November 24 2020
Specs:
i7 6700k @ 4.0ghz
GTX 1070
32gb RAM
Win10
Repro: private
https://devforum.roblox.com/t/repro/887664
select everything in workspace then deselect it.
This is a rough estimate of how my place is when I selected all of the workspace and deselection hanged
There are 4500 instances in the workspace with a terrain of 5024 x112x 5024 .
It hanged for a good minute when I deselected all that.
I am able to select all instances in my game workspace, but deselection causes studio to hang.
My game ( sent in bug file dms)
which is texture heavy and has a little more than the number of selected instances in the reproduction file would hang for about 10 minutes, or indefinitely, it has 4745 items which are parts or models that have parts in them. Terrain also is roughly in size with the repro.