Although a new version of Revit comes out every spring, not all project can be upgraded at the same time. This leads to issues and we have found people accidentally opening files in the wrong version and saving over the original - thankfully it doesn't happen often and the damage has been undone but it's still an issue.
It would be good if Revit automatically appended the Version number to the end of the file once it's opened. For instance Myfile.RVT opened in 2018 would become Myfile_2018.rvt. this is not dissimilar to other packages such as Vectorworks.
If the file is being intentionally upgraded then this would still provide a double check before saving.
