Maybe it's because I'm using a mod (truly endless speed - making the game much slower), but very late in the game when I'm already in the last era - I still get stars and the game every 10 turns asks me to pick a new culture for the VII era. Obviously I can't, but the popup appears every 10 turns and I have to click "remind me later" or "pick new culture" (which does nothing, it just opens the current culture screen). It's getting extremely annoying - is it a known thing in unmodded game, or is it the mod's fault?

No end game conditions chosen, I was just playing as long as I can to see if I can reduce pollution to low levels.