I got the same crashing issue V 3.8, after about 3 Ctrl-z's, Bodyslide will crash. Thought it was just me.
I fixed undo/redo in v3.7.2 once and haven't been getting any crashes myself since, no matter what or how often I undo/redo.
Does it happen to all meshes for you?
What brushes are you using when it crashes?
What tab (meshes, bones, partitions) do you have activated?
Did you brush on multiple shapes at the same time?
Can't remember the specifics but usually i'm in the Meshes tab, using inflate/deflate and smooth the only brushes i use. Top of my head my last crash was Ctrl-Z on the CBBE Hdt body, because i accidentally got the brush to select the body instead of the mesh i was working on, so i tried to back step using Ctrl-z and it crashed, think was only 2 presses of Ctlr-Z that it crashed.
Usually i work on one mesh at a time. Don't know if that helps as i don't really recall the specifics of the crash.
Will try to have a more detailed account next time, sorry.
That's what I do too.
@Vortec do you have multiple outfit studio windows open and or do you leave it up? I tend to leave my computer on and just let it go to sleep. Outfit Studio could be minimized but it's up most of the time as I'm doing new mashups for my game.
I just closed everything and can't reproduce it now. Before closing it I brought up a .nif and got it to crash without editing anything.