خطا در Obsfucate کردن پروژه در اندروید استدیو

سلام دوستان

من برای Obsfucate کردن برنامه توی اندروید استدیو  وقتی میخوام از apk ساین شده رو خروجی بگیرم این ارور رو میده:

Error:Execution failed for task ':app:transformClassesAndResourcesWithProguardForRelease'.> java.io.IOException: Please correct the above warnings first.

این هم کد من که برای پروگارد استفاده کردم :

 # This is a configuration file for ProGuard.
# http://proguard.sourceforge.net/index.html#manual/usage.html

-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-verbose

# Optimization is turned off by default. Dex does not like code run
# through the ProGuard optimize and preverify steps (and performs some
# of these optimizations on its own).
-dontoptimize
-dontpreverify

# If you want to enable optimization, you should include the
# following:
# -optimizations !code/simplification/arithmetic,!code/simplification/cast,!field/*,!class/merging/*
# -optimizationpasses 5
# -allowaccessmodification
#
# Note that you cannot just include these flags in your own
# configuration file; if you are including this file, optimization
# will be turned off. You'll need to either edit this file, or
# duplicate the contents of this file and remove the include of this
# file from your project's proguard.config path property.

-keepattributes *Annotation*
-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgent
-keep public class * extends android.preference.Preference
-keep public class * extends android.support.v4.app.Fragment
-keep public class * extends android.app.Fragment
-keep public class com.android.vending.licensing.ILicensingService

# For native methods, see http://proguard.sourceforge.net/manual/examples.html#native
-keepclasseswithmembernames class * {
    native <methods>;
}

-keep public class * extends android.view.View {
    public <init>(android.content.Context);
    public <init>(android.content.Context, android.util.AttributeSet);
    public <init>(android.content.Context, android.util.AttributeSet, int);
    public void set*(...);
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

# For enumeration classes, see http://proguard.sourceforge.net/manual/examples.html#enumerations
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

-keepclassmembers class **.R$* {
    public static <fields>;
}

# The support library contains references to newer platform versions.
# Don't warn about those in case this app is linking against an older
# platform version.  We know about them, and they are safe.
-dontwarn android.support.**
-dontwarn javax.servlet.**
-dontwarn org.joda.time.**
-dontwarn org.w3c.dom.**
-dontwarn  com.squareup.**
-dontwarn  com.getbase.**
-dontwarn  com.bignerdranch.**
-dontwarn  com.amulyakhare.**
-dontwarn  com.mohamadamin.**