We would like to talk to some current GoToWebinar customers who are interested in playing pre-recorded webinars as live.
If that is you, please email your contact information and the email address to your account to (removed 3/7/17 as we no longer need volunteers)
We've released the Beta Simulated Live GoToWebinar functionality to most customers, should you want to try it out: https://support.logmeininc.com/gotowebinar/help/simulated-live-beta-webinars-g2w090140
Sorry Yoobin--- that problem may be ISP related.
If you search "Simulated Live (Beta) Webinars" on our support page, this will also lead to the same document.
I'm not aware of a limitation of this feature for Mac users. Did you see a document somewhere that stated Simulated Live was restricted to PC Organizers only?
Just visit our support page, then search 'Simulated Live' to locate this new Beta offering for GoToWebinar Organizers. The feature is independent of your operating system / environment, as GoToWebinar does all the hosting and reporting for you.