To be quite honest, the article has explained the reason well. But the error means it’s something with server responding.
looking at update failed, it’ll still fail not because of server responding, but 10MB upload limit. And like i and others said Could you please install it manually?
i have installed manually too, before uploading my query here. but, i am installing it again as you guys said how i can do it properly. I hope it will work.
As everyone has said, this failed due to the fact that the file was over 10Megabytes and the server didn’t know what to do with it;
02 Bad Gateway server error response code indicates that the server, while acting as a gateway or proxy, received an invalid response from the upstream server.
Yes you can, it will not affect the theme, but you will missed some additional new features that can be only found on newest version. Or maybe the old version had some bugs.