Cleartext HTTP traffic to myserver.com not permitted on Android N preview

Try just one line in your Application Tag

android:usesCleartextTraffic="true"

<?xml version="1.0" encoding="utf-8"?>
<manifest ...>
    <uses-permission android:name="android.permission.INTERNET" />
    <application
       ...
       android:usesCleartextTraffic="true"
       ...>
    </application>
</manifest>

There is a known issue in Android N Developer Preview 4 where, if an app modifies its ApplicationInfo.flags, it triggers the blocking of cleartext traffic from the app, even if the app didn't request cleartext traffic to be blocked. The fix is in the next Developer Preview. Thus, this has nothing to do with your Network Security Config. In fact, it looks like you don't even need to declare a custom Network Security Config.

If you can't wait until the next Android N Developer Preview, check your app for places where it modifies its own ApplicationInfo.flags. Typically this takes the form of getApplicationInfo().flags &= ApplicationInfo.FLAG_DEBUGGABLE or getApplicationInfo().flags = ApplicationInfo.FLAG_DEBUGGABLE. The fix for these usages is (getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE).

Alternatively, as a workaround, invoke NetworkSecurityPolicy.isCleartextTrafficPermitted() as early in your app's lifecycle as possible. This workaround should work if invoked before the code which tampers with ApplicationInfo.flags.

android:usesCleartextTraffic="true"

put this line in application tag in manifest file