android studio cant work with new sdk

i have android studio v1.2 with SDK API 15,18,23.i can make project with API15 but when i want to make a project with API 18 or 23 then i face with an error. i did:

1. rebuild project
2. sync gradle
3. reopen android studio
4. download latest sdk tools,api,...

and error is:

Error:A problem occurred configuring project ':app'. Could not resolve all dependencies for configuration ':app:_debugCompile'. Could not resolve com.android.support:appcompat-v7:23.+. Required by: MyApplication:app:unspecified Could not resolve com.android.support:appcompat-v7:23.+. Failed to list versions for com.android.support:appcompat-v7. Unable to load Maven meta-data from jcenter.bintray.com/com/android/support/appcompat-v7/maven-metadata.xml. Could not GET 'jcenter.bintray.com/com/android/support/appcompat-v7/maven-metadata.xml'. Coection to center.bintray.com refused

and in my MainActivity class i have R Error and cant recognize AppCompatActivity

Please Help Me To Resolve This.