RotMG - not loaded: Version loading error, retrying

After I installing Realm of the Mad God via Steam, I always get this error:

Version loading error, retrying...

and after waiting for a long time, restarting, reinstalling and ...; nothing changed!

I also read Loading version error post and applying it - installing many versions of flash players/add-ons/etc - , But I get that error continuously!

Best Answer

I found the answer!

As some sites, protocols or ports that are blocked by many workplaces and school web filters like my workplace, this error will be raise!

I just use an application that Unblock the internet, then error goes away!

But if someone knows witch site, protocol or port is related to add them to add it or those to firewall exception, I will accept his/her answer.

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