Assume that race A is renamed to race B, a race A character saved in existing save data will become invalid because race A is undefined. Some of races like "servant" are hard-coded indeed, but any races can cause the issue. Each character is, however, identified by its integer ID, e.g., 1 is shopkeeper, 2, Zeome, etc. The character name is totally independent of internal integer ID and only displayed. Thus, changing character name does not make save data incompatible.
And yeah, my thought for how to go about it was basically figure out some way to do mapping from 1.89 decompile to Custom to figure out some general hooks, then apply those hooks to 1.90. I just wasn't sure if Bloody already had something similar.
I'm not familiar with E+C source much, but NPC names are not stored in save files, at least in vanilla. If E+ and E+C do so, it's no problem to rename NPCs. Race names, however, are saved in cdatan files and renaming them should cause a compatibility issue like kobolt.
Extract .zip file and overwrite elona_oo_en_hack.exe.
original post here
Good. I'll port it to the next release.
Is it possible to fix those issues via oo_en_hack?
I heard some people reported the same bug. Fortunately, the author of EEx has released fix version.