I have this problem every update, it’s one of the reasons I generally skip a year, along with the pain of migrating extensions/styles/materials. I have not figured out a way to do it gracefully yet. I want to start playing with 2020, I am smiling from ear to ear about the new viewport controls within layout. No more “Modified” ever again, its a dream come true , Thank you Thank you!
But meanwhile I’m still in full workload in the middle of projects using Sketchup 18. I know I can have both running simultaneously on my machine. The problem I have is that once 2020 even exists on my hard drive, all Sketchup files start default opening in 2020. It’ll be weeks before I have all my extensions reinstalled and the toolbars reset the way I need and preferences, materials, bla bla bla, I just can’s start working in 2020. And even if I could do my work in 2020, I end up with a big messy mix of files of different versions.
Is there a way to suppress this behavior and force a Sketchup file to open in the version it was created in?
While writing this I thought I could move the 2020 app onto a removable hard drive so I can play with it but unplug when I want to do real work.