Google Play not connecting showing can't establish a reliable connection?

[AC Question]

Ok so i have samsung galaxy s3 i rooted it a week ago and it worked flawless then afterward when today i opened google play it says no connection .i tried all methods like setting date and time cleaned data and cache but nothing orked the last option i was left with was factory reset i did it but nothing worked when it restarted it asked for google account and when i tried to sign in it prompt saying cant establish a reliable connection .Now when i researched more about it i came to know about a file hosts and to edit it i installed total commander when i tried to edit it it closed saying not enough memory but when i opened it with es file explorer it opened when i put a # mark before everything and saved it it gives an error saying it cannot be save
file size of hosts is 1.1mb
please help any help will be appreciated

 

[Rukbat]

1) The hosts file can only be edited if you're rooted.

2) The hosts file just speeds up the connection process by not having to ask a DNS server for the address of the site (if you have that site in the file) and it can block sites by saying that your phone is the address of the site (which is how a lot of ad blockers work - they refer all known ad hosting sites to your phone). Not even having a hosts file won't cause a problem - the default hosts file is a few lines of comments, and most computers never have it changed.

3) If your wifi Advanced settings has a setting for auto network switching, turn it off.