when i open unity on my macbook pro i get a error saying transaction is invalid i re-instaled it 3 times and im still getting the error
Just got the same problem. Also with different installations of Unity; with ML 10.8.5 and Mavericks 10.9.1.
Cookies in Safari(.app) needs to be activated.
Unity is trying to access their hypertext document for licensing via web view. The web view of your operating system uses the standard implemented browser. The license document handles data via cookies and if you block or just disallow some (maybe from third) cookies, Unity isn’t able to handle this and throws an Error.
As you see: If there are more people, who restrict their Safari settings, this error should be throws more often. But it seems, nobody is changing the Safari’s default settings.
I have the same problem! I don’t know what it is, sorry.