I found a fix to a very similar problem here https://forums.totalwar.org/vb/showt...=1#post1433613

I basically did what Oleo said:Made a copy of Rome Data\EB\Data\world\maps\campaign\imperial_campaign and renamed it barbarian_invasion

Made a copy of Rome Data\EB\Data\text\imperial_campaign_regions_and_settlement_names.txt and renamed it barbarian_invasion_regions_and_settlement_names.txt

Deleted Rome Data\EB\Data\world\maps\base\map.rwm

Loaded the EB mod through Barbarian Invasion. The campaign seems to work fine but the historical battles screen is still empty.

I'm using a direct download version of RTW. Not the CD. Don't know if that's important. Many thanks to Edwin, Feral and all the moders!