The problem is caused because the code you are running was created in an older API level, And your present SDK Manager doesn't support running them. So do try the following; 1.Install the SDK Manager that support API level 23. Go to >SDK Manager, >Android SDK , then select API 23 and install. 2.second alternative is to update your build.grade app module to change compileSdkVersion,compile,and other numbers to your currently supported API level.
Note:please ensure to check the API and Revision numbers and change them exactly. otherwise Your project won't synchronize