I wish this help you If anyone stumbles on this in the future I want to make sure that you can get an answer... The problem was that certain tags that are available only to Material and Android 5.0+ were being used in my styles. So I instead made a res/values-v21/styles.xml folder and put my appropriate settings in there. That fixed the issue.
Choose the language of the android application on start of activity
like below fixes the issue I want to set the language of my application choosed at start of activity, the value of this language is defined in SharedPreferences , ok try to change your code like that :
Resources res = getResources();
// Change locale settings in the app.
DisplayMetrics dm = res.getDisplayMetrics();
android.content.res.Configuration conf = res.getConfiguration();
conf.locale = new Locale("put the value that u get from SharedPreferences);
change application language in start activity using SharedPreferences?