Cannot acces ActivityCompatApi23 when trying to use FragmentActivity

Question

I'm trying to use a ViewPager on my smartwatch, but I keep getting an error when trying to rebuild/run/debug my application. I'm using a FragmentActivity, which is where the error occurs. I searched stackoverflow and tutorial websites to see what could be the problem, and a lot of results are related to the build.gradle files. However I tried pretty much everything I stumbled upon, but the error didn't change once.

The error:

Error: Cannot acces ActivityCompatApi23

The error happens on this line, coming from the piece of code below.

public class WearMainActivity extends FragmentActivity {

WearMainActivity.java

package be.ehb.dt.finalwork_lievenluyckx_v001;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;

import java.util.List;
import java.util.Vector;

/**
 * Created by Lieven on 14/08/17.
 */

public class WearMainActivity extends FragmentActivity {


    private PagerAdapter pagerAdapter;

    /* (non-Javadoc)
      * @see android.support.v4.app.FragmentActivity#onCreate(android.os.Bundle)
      */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.viewpager);
        //initialsie the pager
        initialisePaging();
    }

    /**
     * Initialise the fragments to be paged
     */
    private void initialisePaging() {

        List<Fragment> fragments = new Vector<Fragment>();
        fragments.add(Fragment.instantiate(this, Monitor.class.getName()));
        fragments.add(Fragment.instantiate(this, CurrentSongOverviewWear.class.getName()));
        this.pagerAdapter  = new MyPagerAdapter(getSupportFragmentManager(), fragments);

        ViewPager pager = (ViewPager) findViewById(R.id.viewpager_container);
        pager.setAdapter(this.pagerAdapter);
    }
}

build.gradle (WEAR)

apply plugin: 'com.android.application'

android {
    allprojects {
        repositories {
            jcenter()
            maven {
                url "https://maven.google.com"
            }
        }
    }

    compileSdkVersion 25
    buildToolsVersion "25.0.1"
    defaultConfig {
        applicationId "be.ehb.dt.finalwork_lievenluyckx_v001"
        minSdkVersion 25
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"

    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

}

dependencies {
    compile 'com.android.support:wear:26.0.0'
    compile 'com.android.support:appcompat-v7:25.1.1'
    compile 'com.google.android.support:wearable:2.0.3'
    compile 'com.google.android.gms:play-services:11.0.4'
    provided 'com.google.android.wearable:wearable:2.0.3'
    compile 'com.android.support:support-v4:26.0.0-alpha1'
}

Answer 1

Following Eugen Pechanec's explanation (as a comment below the original post) fixed the problem for me:

All support libraries need to be same version. If your compile SDK is 25, it's 25.4.0. If your compile SDK is 26, it's 26.0.1. Don't mix them.