Why does an empty project cause a Windows Firewall warning?

To reproduce, create a new project with nothing in it whatsoever. Create a web player build. Go into windows firewall and remove any inbound rules for the browser you want to use. Open up the build in your browser (doesn’t seem to make a difference whether it’s hosted on a server or local). You see the unity splash screen and loading bar, and before the loading bar even begins to progress you get an ugly windows firewall warning. Clicking allow, you then get an exception added to your inbound windows firewall rules.

So, why does unity require an inbound connection rule? Also, there are other unity games I’m able to play on facebook that don’t seem to generate this warning. How are they getting around it??

i know for sure that the unity web player is connecting some where to the web to check if it need update. then if update to the player is needed he start to update the player before downloading the game. the update is not always happen, it depend on what player version the game build require.

this could be the answer why the player need network access before he start downloading the game and why some times it just work.

so how do i know that? in my work network most of online unity games are blocked because the player can’t do online update (the player load, then i get an error that i need to update it) but if i try to load old game the web player works fine…

at the bottom line, it’s all my theory.

Maybe cause of antivirus. If You has McAfee LOL, Uninstall it