Re: SIMS 3 (Mac) disc not recognised
The EULA (end user license agreement) - you know that thing you agree with when you install the game - grants a license to you and you only. When you buy the Sims 3 game you do not own the software. What you own is a license to use the software in such way as stated in the agreement. You can redeem the code to allow download of the digital version. That code would be tied to a (one) Origin account and that Origin account can only be opened by one user at a time. It will still run on both computers except only one person can log into Origin at a time. With the disc version you need to have the latest released to market disc in the drive to play the game. It is against forum rules to discuss violating the terms of use.
Some dvd drive models are known to have trouble with TS3 discs. Some won't read them at all and others stop reading them after some time. Do your discs be read in another computer? Do other discs work in the drive? If the drive is bad you can replace the drive or get a usb dvd drive. I can not discuss any way to play the game that is not in the legal manner.
good luck