Hey guys, first of all I'm sorry for my English. I have a MBP 13in early 2015 running El Capitan 10.11.5. My network stops working after a while of usage, wifi sign still shows connected but Safari cannot open any site nor sending/receiving email via Mail. And Mail also shows an issue sign next to the Inbox. I have tried to find solutions for the issue but any of them could have fixed it. I really appreciate any help. Thanks.