Just Making Sure I've Got the Order Right.

Allright guys,
I'm using the base game with expansions: outdoor stuff* world adventures, ambitions* and late night. I was just making sure that I HAVE TO INSTALL Ambitions in order to make Late Night work. I realize that there are a billion threads on this topic, but I couldn't find any that confirmed that you must download this. I just don't want the game to give me the unable to start error again after the sixth time uninstalling and re-installing all of this stuff. Any response would be appreciated. Also, I've only downloaded Outdoor Stuff, Ambitions and Late Night from the games4theworld site, I didn't want to take up any more bandwidth and from what I gather, the base game and world adventures do not need to be downloaded from the site.
* - downloaded solely for the purpose of the installation guide, not for personal pleasure

Hello,

Things have changed, please read this: https://games4theworld.forumotion.com/t1171-must-read-how-to-install-the-sims-3-correctly-must-read

you're the boss admin, ill come back to this thread if I have any problems