[Dan_]

Baron Grazic: Empire files created in older versions were likely to have been used in the last game since it took a while to get started and there were a lot of players. Normally I would be surprised if this caused an issue as it is trivial record and check the version of any data files (empire file) and halt on version mismatches.
The test game I ran with designs disappearing (#2) was all done with the same version.

What does happens when empire file created in an older version is used in an updated version of SEV?

I'm sending a link to this forum topic to Strategy First and Malfador support so they can provide some answers.