So an inherent risk of using mods is that it might make your saves incompatible with the base game. Caribdis (the developer of Eternum) can't really help you fix saves that break in that way. We have tested the current version of the mod with the latest release of Eternum (0.7.5) and have verified that both modded saves work in unmodded games and unmodded saves work in modded games. This *could* change when the new release comes out this fall, but I think it is unlikely. If you run into any issues let me know and I can probably fix your save for you.