[Edi]

The problem is the way the descriptions are hardcoded in the files. The descriptions are tied to eras instead of the nation number. If you simpluy switch two nations between different eraas like I did with Ermor in the Restoration mod, the descriptions stay in place, so e.g. in my mod Ashen Empire in MA had the description of Broken Empire and the modified Broken Empire had the Ashen Empire description. So if you move a nation out of its own era, you need to write out the full description in the mod file, as well as the summary and brief descriptions too.