Proguard ClassCastException in Mobile First Server 7.1 - ibm-mobilefirst

Question

I am getting ClassCastException while exporting android hybrid app as apk in Mobile First Server 7.1
Followed below links for enabling Proguard in MFS.
https://www.youtube.com/watch?v=WrCmLJuIMuk
https://www.ibm.com/support/knowledgecenter/SSHS8R_7.1.0/com.ibm.worklight.deploy.doc/admin/t_pg_creating_obfus_apk.html
Find below console error logs
[2016-06-21 11:57:47 - ProguardProguardAndroid] Proguard returned with error code 1. See console
[2016-06-21 11:57:47 - ProguardProguardAndroid] Note: there were 2640 duplicate class definitions.
[2016-06-21 11:57:47 - ProguardProguardAndroid] You should check if you need to specify additional program jars.
[2016-06-21 11:57:47 - ProguardProguardAndroid] java.lang.ClassCastException: java.lang.Object cannot be cast to java.lang.String
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.obfuscate.MemberObfuscator.newMemberName(MemberObfuscator.java:198)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.obfuscate.MemberNameCollector.visitAnyMember(MemberNameCollector.java:74)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.util.SimplifiedVisitor.visitProgramMember(SimplifiedVisitor.java:79)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.util.SimplifiedVisitor.visitProgramMethod(SimplifiedVisitor.java:91)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.visitor.MemberAccessFilter.visitProgramMethod(MemberAccessFilter.java:90)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.ProgramMethod.accept(ProgramMethod.java:71)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.ProgramClass.methodsAccept(ProgramClass.java:504)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.visitor.AllMemberVisitor.visitProgramClass(AllMemberVisitor.java:48)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.ProgramClass.accept(ProgramClass.java:346)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.ProgramClass.hierarchyAccept(ProgramClass.java:359)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.LibraryClass.hierarchyAccept(LibraryClass.java:371)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.ProgramClass.hierarchyAccept(ProgramClass.java:416)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.visitor.ClassHierarchyTraveler.visitProgramClass(ClassHierarchyTraveler.java:75)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.visitor.MultiClassVisitor.visitProgramClass(MultiClassVisitor.java:85)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.ProgramClass.accept(ProgramClass.java:346)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.classfile.ClassPool.classesAccept(ClassPool.java:116)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.obfuscate.Obfuscator.execute(Obfuscator.java:217)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.ProGuard.obfuscate(ProGuard.java:333)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.ProGuard.execute(ProGuard.java:135)
[2016-06-21 11:57:47 - ProguardProguardAndroid] at proguard.ProGuard.main(ProGuard.java:492)
Find below for contents for proguard-project.txt
# To enable ProGuard in your project, edit project.properties
# to define the proguard.config property as described in that file.
#
# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in ${sdk.dir}/tools/proguard/proguard-android.txt
# You can edit the include path and order by changing the ProGuard
# include property in project.properties.
#
# For more details, see
# http://developer.android.com/guide/developing/tools/proguard.html
# Add any project specific keep options here:
# If your project uses WebView with JS, uncomment the following
# and specify the fully qualified class name to the JavaScript interface
# class:
#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
# public *;
#}
-injars bin/classes
-injars libs
-outjars bin/classes-processed.jar
# Using Google's License Verification Library
-keep class com.android.vending.licensing.ILicensingService
# Specifies to write out some more information during processing.
# If the program terminates with an exception, this option will print out the entire stack trace, instead of just the exception message.
-verbose
####################################################################################################
############################## IBM MobileFirst Platform configuration ############################
####################################################################################################
# Annotations are represented by attributes that have no direct effect on the execution of the code.
-keepattributes *Annotation*
-keepclassmembers enum * {
public static **[] values();
public static ** valueOf(java.lang.String);
}
-keepattributes InnerClasses
-keep class **.R
-keep class **.R$* {
<fields>;
}
# These options let obfuscated applications or libraries produce stack traces that can still be deciphered later on
-renamesourcefileattribute SourceFile
-keepattributes SourceFile,LineNumberTable
# Enable proguard with Cordova
-keep class org.apache.cordova.** { *; }
-keep public class * extends org.apache.cordova.CordovaPlugin
-keep class com.worklight.androidgap.push.** { *; }
-keep class com.worklight.wlclient.push.** { *; }
-keep class com.worklight.common.security.AppAuthenticityToken { *; }
# Enable proguard with Google libs
-keep class com.google.** { *;}
-dontwarn com.google.common.**
-dontwarn com.google.ads.**
# apache.http
-keep class org.apache.http.** { *; }
-dontwarn org.apache.http.**
-optimizations !class/merging/vertical*,!class/merging/horizontal*,!code/simplification/arithmetic,!field/*,!code/allocation/variable
-keep class net.sqlcipher.** { *; }
-dontwarn net.sqlcipher.**
-keep class org.codehaus.** { *; }
-keepattributes *Annotation*,EnclosingMethod
-keepclassmembers enum * {
public static **[] values();
public static ** valueOf(java.lang.String);
}
# These classes contain references to external jars which are not included in the default MobileFirst project.
-dontwarn com.worklight.common.internal.WLTrusteerInternal*
-dontwarn com.worklight.jsonstore.**
-dontwarn org.codehaus.jackson.map.ext.*
-dontwarn com.worklight.androidgap.push.GCMIntentService
-dontwarn com.worklight.androidgap.plugin.WLInitializationPlugin
-dontwarn com.worklight.wlclient.push.GCMIntentService
-dontwarn org.bouncycastle.**
-dontwarn com.worklight.androidgap.jsonstore.security.SecurityManager
-dontwarn com.worklight.wlclient.push.WLBroadcastReceiver
-dontwarn com.worklight.wlclient.push.common.*
-dontwarn com.worklight.wlclient.api.WLPush
-dontwarn com.worklight.wlclient.api.SecurityUtils
-dontwarn android.support.v4.**
-dontwarn android.net.SSLCertificateSocketFactory
-dontwarn android.net.http.*
######################################################################################################
-dontwarn android.**
-keep class android.**
-dontwarn com.android.**
-keep class com.android.**
-dontwarn com.google.**
-keep class com.google.**

Answer 1

I downloaded updated proguard from https://sourceforge.net/projects/proguard/files/proguard/. Replaced bin and lib folders of my proguard with downloaded ones. Proguard folder located in /android-sdks/tools/proguard
This resolved my issue.