Ok, I've had this expansion pack for a while now, but haven't been able to use it because of the 'Wrong Region Code' error.
On my old computer i had the same problem, but googled it and found out how to use the regedit thingy mabob and change the region code.
HOWEVER; on my current computer (windows 7 if that makes any difference) there is no Sims folder ANYWHERE in the registry... help? :(Sims 3 World Adventures region code?
Not sure if this is the same issue but I had problems with the Sims 3 Expansion Pack and incorrect region codes.
I fixed it with a simple registry edit:
1. Click windows start button and select run.
2. Type “regedit” and click on ok
3. Your computer may ask you for permission to continue, just click ok if asked
4. In the left hand pane, click the arrow next to HK_LOCAL_MACHINE
5. Click the arrow next to SOFTWARE
6. Click the arrow next to The Sims
7. Click on The Sims 3
8. In the right hand pane, double- click on SKU
9. Change the value to either 1 or 2 or 7 (depending on your version of expansion pack*.)
10. Close the registry editor and try again to install the expansion pack.
* Region Codes
1 = US
2 = UK
7 = Asian
Hope this helps