Httprequestexception: Could Not Head Warning In Android Studio 3.1.1 (but Sync Successfully)

Hi I facing a problem while syncing the project. I am getting warning after sync successfully I don't know why I am getting this warning. If click on warning in build window than

Solution 1:

I fixed this problem by File -> Settings -> Tools -> Server Certificates -> Accept non-trusted certificates automatically

Solution 2:

Make sure you are connected to Internet and if you are connected to Internet then your Internet firewall is forbidding to make connection with https://jcenter.bintray.com. Try to sync with different Internet connection.

I had same problem while upgrading gradle version in my office Internet but when I tried with by personal Internet connection it went softly.