Three of my rabbit holes (Science Lab, Stadium and Abandoned Warehouse) are appearing as regular community lots in my Sims Game and when I go to reassign them to the correct lot types, none of those three lot types appear in the list.

I have only just started playing this game again after a year and I really want to get back into playing it.
Please may someone help me?

You need to put rabbit holes on lots that are assigned as either Visitors Allowed or No Visitors Allowed. The only exceptions are for the mausoleum and Vault of Antiquity rabbit holes, which can be placed on any type of community lot (although mausoleums were designed for graveyards).

Rabbit holes conflict with every other lot type.

I tried that and failed miserably.
The Rabbit Holes are the ones that came in the towns, not ones I added

Here's a screenshot of my problem, with Islo Paradisio's Scence Lab:


Maybe I should try and do a clean uninstall and re-install, this will be my first time cleaning the registry, I'm such a noob.

Well what do you know, it really was a mod conflict =D
Thanks :D

Now to find a mod conflict detector for the Sims 3 (I got one for TS4)
Thank you so much, You just saved me a reinstall :D

EDIT: All fixed =D Thank you so much HuG Now I can play as much TS3 as I please =D

EDIT 2: Now my sims refuse to enter those lots...they keep on saying it's blocked, tried changing to visitors allowed and everything...
EDIT 3: Played without mods again, it is another conflict.

I wish there was an up-to-date mod conflict detector for TS3....I could use one by now.

There you go: It's pretty much one of the most important tools you can have for your CC and mods.
http://www.modthesims.info/d/387006

I think I found out the problem, it was corrupt save files.
I started a new game and my sim entered one of the Rabbit holes.