@peterjwinberg wrote:
I ran into this during a 2018 Architecture trial last year, but we stayed (for the time being) with 2015 vanilla. I only worked on, and "down saved" (save as 2013 dwg), a handful of files from '18 Architecture, and each one showed this error message whenever I copy-and-pasted objects in '15 vanilla.
While in '15, I had to wblock the "entire drawing" of each file, and that seemed to do the trick. Fields, xref's, sheet layouts... all carried over fine. I had other users test the files before overwriting (although I'm still keeping an archive just in case). So far so good - no more error message.
That's because WBlock creates the file from scratch, a truly blank template, and you are not using any objects that utilize newer features. It will probably continue to work until you try to use one of those newer objects in one of those blocks. At that point, you will need to convert the drawing, one way or another, for it to be fully compatible with older versions. You might as well put into practice converting or exporting as has been suggested many times by many people regarding this topic.
Rob
Drafting is a breeze and Revit doesn't always work the way you think it should.