Android can not modify a textview

I have a TextView that is not updated at runtime. Said TextView is defined by the following XML code:

<TextView
android:id="@+id/agi_val"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />

In the code of the activity, I access the TextView in this way:

private TextView AGI;
///< Some stuff

 protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_abf__char_gen__basic_info);

        abfToolsSaveData = (ABFToolsSaveData) getIntent().getParcelableExtra("SaveDataClass");

        this.AGI = (TextView) findViewById(R.id.agi_val);
        ///< Some stuff

        if (abfToolsSaveData != null) {
            this.chargeData(true);
        } else {
            Log.d("INFO", "abfToolsSaveData is null");
        }
    }

And in chargeData (boolean):

public void chargeData(boolean firstTime){
        if(firstTime){
            MainCharacteristics mc = abfToolsSaveData.getCharacter().getMainCharacteristics(); ///< We get the main characteristics, auto-generated the first time

            /**
             * Set the Text Views with the default value
             */
            if(AGI != null){    ///< I've done this to check if the text view is null or not
                Log.d("INFO", String.valueOf(AGI));
                AGI.setText(mc.getAGI());
            }
            else
                Log.d("INFO","AGI IS NULL");
            ///< Some stuff
        }
    }

The thing is that "agi_val" finds it, but the AGI TextView of the activity can not access the agi_val resource. The error log is as follows:

///< Esta primera linea es mi salida por pantalla que demuestra que AGI tiene acceso a agi_val:
    09-20 10:07:32.344 1266-1266/com.noeselmastersonlosdados.sliferdragon.penandpapercompanion D/INFO: android.support.v7.widget.AppCompatTextView{b670993 V.ED.... ......ID 0,0-0,0 #7f0d0077 app:id/agi_val}
    09-20 10:07:32.344 1266-1266/com.noeselmastersonlosdados.sliferdragon.penandpapercompanion W/ResourceType: No package identifier when getting value for resource number 0x00000009
    --------- beginning of crash
    09-20 10:07:32.347 1266-1266/com.noeselmastersonlosdados.sliferdragon.penandpapercompanion E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.noeselmastersonlosdados.sliferdragon.penandpapercompanion, PID: 1266
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.noeselmastersonlosdados.sliferdragon.penandpapercompanion/com.noeselmastersonlosdados.sliferdragon.penandpapercompanion.ABF_CharGen_BasicInfo}: android.content.res.Resources$NotFoundException: String resource ID #0x9
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
    at android.app.ActivityThread.access$800(ActivityThread.java:151)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:135)
    at android.app.ActivityThread.main(ActivityThread.java:5254)
    at java.lang.reflect.Method.invoke(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:372)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
  Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x9
    at android.content.res.Resources.getText(Resources.java:299)
    at android.widget.TextView.setText(TextView.java:4132)
///< Esta linea referencia a la asignación del texto
    at com.noeselmastersonlosdados.sliferdragon.penandpapercompanion.ABF_CharGen_BasicInfo.chargeData(ABF_CharGen_BasicInfo.java:73)
    at com.noeselmastersonlosdados.sliferdragon.penandpapercompanion.ABF_CharGen_BasicInfo.onCreate(ABF_CharGen_BasicInfo.java:54)
    at android.app.Activity.performCreate(Activity.java:5990)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
    at android.app.ActivityThread.access$800(ActivityThread.java:151) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:135) 
    at android.app.ActivityThread.main(ActivityThread.java:5254) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:372) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 

Does anyone know what is happening? I have tried to do a Clean and Rebuild, to restart the program, and many other things that I have found online, but nothing gives me the solution to the problem.