I can't start The Sims 3 with mods installed. HELP!

[Ellephant]

Every time I try and start The Sims 3 I get a message saying I have unauthorised content, and do I wish to quit. If I click no the loading screen starts but after about 2 seconds another message appears saying I have a problem with a code, which means my mods, and it asks if I want to debug it, no matter which option I click it shuts down The Sims 3. I don't want to delete my mods but thats the only way I've gotten it to work. Please help. Is there some kind of override I can use? or something. Thanks.
Note: I tried to download store content before this happened.

[Mootilda]

Did you download the store content legally or illegally? If illegally, then the message makes perfect sense. If legally, then I would contact EA and ask them for help.

[Ellephant]

it wasn't the store content that wouldn't work, its the mods. I was trying to download stuff from the Sims Store on their website, free stuff, like the new cars they uploaded.