It a quite common mistake but while dealing it for the first time it took me hours to solve .Here is the solution which worked for me..

Here error in this particular statement.

getLoaderManager().initLoader(EXISTING_REMINDER_LOADER, null, this);

Basically its problem with import statements.

For me first I was using these import statements

import android.support.v4.app.LoaderManager;
import android.support.v4.content.Loader;

I replaced these with :

import android.LoaderManager;
import android.content.Loader;

Then all worked fine. 😀