Re: I bought Monte Vista off the official website and it downloaded onto my downloads, it installed but when i play, nothing comes up.

it is 1.50.56.021002 so 1.50 i think? 

it is 1.50.56.021002 so 1.50 i think? also, if i go to AddOns to check what base version it is, its not in that folder? so that is just the normal version for sims 3

On PC's there's log file, not sure if it applies to macs though

The log can be found in documents/electronicarts/thesims3 and is called Sims3LauncherLogFile.log

Post the content here

i found the Sims3LauncherLogFile.log and this is what it had in it

2013/01/16|03:39:03|OFB-SIM3:43457|Store Download Failure. Failed to find Sims3 pack data||||Build Version: 1.47.6.020002|Platform: Mac|Locale: en_US|Content URL: http://store.thesims3.com|Web Services URL: http://igs.thesims3.com|
2013/01/16|04:01:47|OFB-SIM3:43457|Store Download Failure. Failed to find Sims3 pack data||||Build Version: 1.47.6.020002|Platform: Mac|Locale: en_US|Content URL: http://store.thesims3.com|Web Services URL: http://igs.thesims3.com|
2013/01/16|21:04:10|OFB-SIM3:43457|Store Download Failure. Failed to find Sims3 pack data||||Build Version: 1.47.6.020002|Platform: Mac|Locale: en_US|Content URL: http://store.thesims3.com|Web Services URL: http://igs.thesims3.com|
2013/01/20|04:41:01|OFB-SIM3:43457|Store Download Failure. Failed to find Sims3 pack data||||Build Version: 1.47.6.020002|Platform: Mac|Locale: en_US|Content URL: http://store.thesims3.com|Web Services URL: http://igs.thesims3.com|
2013/06/06|05:22:52|OFB-SIM3:58951|Store Download Failure. Expected more bytes from the server.||Missing 2852990 bytes. Server download content 226841535 bytes. For entry #60/114 expected 4374216 but received 1521226 bytes.|http://na.lvlt.sims3store.cdn.ea.com/s/p/sims/sims3/sims3store/objects/MonteVista_World/MonteVista_World.Sims3Pack?nvb=20130606050023&nva=20130606065023&token=0906948b850cbfa9fd626|Build Version: 10.0.96.021001|Platform: Mac|Locale: en_US|Content URL: http://store.thesims3.com|Web Services URL: http://igs.thesims3.com|

Looks like a server issue. Make sure nothing is blocking the connection. Might be a server hiccup. Try aging.