No Heroes for Karl or Gustav Guns?

[RandomAttack]

I recently have been replaying some saved games from original campaign, post-Sevastopol, and can no longer assign or reassign heroes to these units. Get a message that says "this command is disabled by one of units traits", and all the heroes are grayed out. But I don't see any such "new" trait. I can leave the originally assigned heroes on them, but if I remove them then that's it-- cannot reassign a hero to them. Did one of the updates change this?

[RandomAttack]

C'mon guys-- is this a bug or is it a "feature" via an update?

[DefiantXYX]

Not sure, but I think its a feature that came with an update. You could "heal" the gun with heroes or make it even stronger, I think that was not intended.

[RandomAttack]

Thanks! I can live with that-- unless it was a nasty bug! : )