Android Errors in released app with ProGuard

I have done a app in which I am Using EPSON Printer SDK So there I Have some Library files for EPSON thermal printer I am using them In my app

So here App is running Successfully and I am printing the data

Now I made a Release Version of my apk and Signed it

My app is in different package(com.mytest.mapp) and printer is in other package ( and I am using library

So its crashing when I try to print the application

I followed many proguard forms and I have added this in proguard-rules

-keep class** {

But am still facing same issue when minifyEnabled true

If its false its working fine for Release version can any 1 suggest me what I am missing for EPSON SDK library

This is my error Log

   No pending exception expected: java.lang.ClassNotFoundException: Didn't find class "" on path: DexPathList[[zip file "/data/app/com.mytest.mapp-1/base.apk"],nativeLibraryDirectories=[/data/app/com.mytest.mapp-1/lib/arm, /vendor/lib, /system/lib]]
   at java.lang.Class dalvik.system.BaseDexClassLoader.findClass(java.lang.String) (
   at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String, boolean) (
   at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String) (
   at java.lang.String java.lang.Runtime.nativeLoad(java.lang.String, java.lang.ClassLoader, java.lang.String) (
   at java.lang.String java.lang.Runtime.doLoad(java.lang.String, java.lang.ClassLoader) (
   at void java.lang.Runtime.loadLibrary(java.lang.String, java.lang.ClassLoader) (
   at void java.lang.System.loadLibrary(java.lang.String) (
   at void<clinit>() ((null):-1)
   at void com.mytest.mapp.pdata.PrintMActivity.onCreate(android.os.Bundle) ((null):-1)
   at void (
   at void, android.os.Bundle) (
   at$ActivityClientRecord, android.content.Intent) (
   at void$ActivityClientRecord, android.content.Intent) (
   at void$900(,$ActivityClientRecord, android.content.Intent) (
   at void$H.handleMessage(android.os.Message) (
   at void android.os.Handler.dispatchMessage(android.os.Message) (
   at void android.os.Looper.loop() (
   at void[]) (
   at java.lang.Object java.lang.reflect.Method.invoke!(java.lang.Object, java.lang.Object[], boolean) (
   at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (
   at void$ (
   at void[]) (


I also Got Same error With Bluetooth printer and Epson Printer.. Better to use

-ignorewarnings / -dontwarn class/package name
-keep class * {
    public private *;

Dot forget to Keep our class/package name

Hope this works

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