Hello isenchine thank you very much for the help, I will give it a try! 
I have another question about this matter, so maybe this way around might also "fix" this problem:
What if I start a new game but turn all the victory conditions off, so there is actually no real way to win this game? And if I would do so then what if I get to the year 2020 AD when Civilization 4 normally sais the game is finally over? Would a text message still appear, besides the fact that I have turned all the victory conditions off? And would my game still get into the highscores, although there was no victory condition to achieve? It never happened to me like this before because I always play marathon games and normally I achieve victory already before the very last year (mostly by conquering all the other civilizations).

I have another question about this matter, so maybe this way around might also "fix" this problem:
What if I start a new game but turn all the victory conditions off, so there is actually no real way to win this game? And if I would do so then what if I get to the year 2020 AD when Civilization 4 normally sais the game is finally over? Would a text message still appear, besides the fact that I have turned all the victory conditions off? And would my game still get into the highscores, although there was no victory condition to achieve? It never happened to me like this before because I always play marathon games and normally I achieve victory already before the very last year (mostly by conquering all the other civilizations).




I play the "Ultimate Edition" of Civilization 4, you know the package with Civilization 4 and both of its addons Warlords and Beyond the Sword. And my current game is played with the main game, not with the addons. No mods and no fanpatches. Everything clean as it has been given to the people from Firaxis. 
you have. Improve it by getting more
(e.g. by building recycling centres, trading away oil, or by whipping away population). Being number 1 in this isn't important. 