We upgraded to 2018 last week, and now under external references settings, the Don't prompt to save read-only files (Discard Changes) button no longer works. When you go to save a copy, you will get any sub-assembly asking you to save that you don't want to save/change. This seems to be related to the versions of the files being on 2017. IT is completely frustrating to have to cancel out of a million save windows to save copies now. I know there is a script that you can run to update all files, but that will take multiple computers for multiple hours! Quite a disruption!. Anyone found a quick fix for this?