My .kprx is 6 meg (largest we have), targeting .net framework 4.0 and VS2015 crashes/restarts itself after successful build.
VS2015 crashes/restarts itself after running Deploy Package command successfully.
If I target .NET 4.5.2 it reports a lot of deprecated methods warning then VS2015 crashes/restarts itself.
My machine has 32GB memory and I was able to deploy a smaller process last week with the same VS2015 update 3 without this issue.
I am running update 3 but actually haven't used anything lately other than Smart Object project items as we aren't to workflow yet. I'd suggest running a repair on the K2 client components as I have ran into issues with the K2 bits not being right with Visual Studio after the Update 3. Also, I'd open a ticket with K2 Support so that the issue can be tracked and you can get help if the repair of the K2 Client bits does not help.