@Sckipjack wrote:
That seems to be the only remedy now. I wasn't having this issue on any of
the past updates so I will have to revert to this method.
I'm surprised this has never happened to you before. This happens to me all the time. It's actually a good thing if you need to edit and return the file. Revit is not backward compatible. You don't want to upgrade it to the "wrong" version, work on it and return the file.
The message is being thrown because you are trying to open a version of Revit that was created in a later version than the currently opened session version. It's not a show-stopper though. Just launch a session that is compatible and open the file in that one.
If you don't know what the version is, another way to find out what it is, is to temporarily change the file extension from "rvt" to "txt", open it in Notepad and Find "B U I L D".