Hi, I have the Super Collection (I'm on Mac) and I downloaded a lot of mod for this game, but since a certain time, none of my sims fall in love again, I can only play with the actual sims that already have a relationship, but the ones that are singles ? Nope they consider their "love interest" like their BFF, it's just impossible to make them fall in love. I did it with adult, teenager, none of them won't fall in love !

Well you mentioned that you installed a lot of mods, so the first thing to do is make a back up and then take out all of your mods and start the game and check to see if your sims will fall in love. Maybe create a couple of new Sims and test them.

If the problem goes away, and most likely it will, then you have either an incompatiable mod or two or more conflicting mods.

Well, since I installed some ACR mod and Pescado's mod "nomoretownie" that were two big mod for my game, and since these ones, they don't fall again in love, I removed them but, the ACR seems to still be here and still don't work.

The original ACR, which I'll call ACR1.0, has to be uninstalled from every neighborhood before you remove it from Downloads. The Pescado mod is notownieregen. Are you maybe thinking of noinstantloves which was also made by Pescado? That's the one that's intended to slow or stop sims from falling in love. Really, you should pull your entire The Sims 2 folder, move it to your desktop, re-start the game, and then try making two sims in one of the default neighborhoods fall in love. If that works, then you have to identify which mod is causing your problem. The Hack Conflict Detection Utility (HCDU) doesn't run on Macs so you'll have to do the 50/50 method on this page. I suggest you work through the whole page, except you can skip the HCDU section. But work through the rest of it, it should help.

From ACR's page:
http://www.simbology.com/smf/index.php?topic=19.0
"If you are installing for the first time, you should spawn an adjuster (click on the active sim and select adjust...casual romance -> spawn adjuster) and run setup neighborhood from the tokens...hood menu before the mod will completely work as designed. The mod will install the tokens automatically at 8:30am/pm however if you don't before then."

Maybe you didn't let the game run long enough for it to do it automatically or it just didn't happen for whatever reason? I had that same thing happen in my game and the missing tokens was the reason my Sims couldn't fall in love for me but giving them tokens fixed it.