java.lang.RuntimeException: stub only when proguard enabled true

Question

I've written a sample app in which I'm getting data from localhost... created this app a year ago and last I used last week or max to max 2 weeks ago, and app was doing good, everything as per my expectation

UPDATE

Resolved this issue by disabling proguard, but I want to enable like, I've enabled earlier

Suddenly, app has stopped fetching data from localhost, can't see more, but this is what I found in Log:

2020-06-23 15:25:51.666 3751-3751/? W/RefBase: CallStack::getCurrentInternal not linked, returning null
2020-06-23 15:25:51.666 3751-3751/? W/RefBase: CallStack::logStackInternal not linked
2020-06-23 15:25:51.687 27221-27221/? W/ContextImpl: Calling a method in the system process without a qualified user: android.app.ContextImpl.startService:1631 android.content.ContextWrapper.startService:683 android.content.ContextWrapper.startService:683 com.sec.android.diagmonagent.sa.receiver.CFLogReceiver.sendCFLog:21 com.sec.android.diagmonagent.sa.receiver.CFLogReceiver.onReceive:13 
2020-06-23 15:25:51.705 19718-19718/com.example.myapp W/System.err: java.lang.RuntimeException: stub
2020-06-23 15:25:51.705 19718-19718/com.example.myapp W/System.err:     at c.e.b.a.<init>(:36)
2020-06-23 15:25:51.705 19718-19718/com.example.myapp W/System.err:     at com.example.myapp.UserInfoActivity$e.<init>(:362)
2020-06-23 15:25:51.705 19718-19718/com.example.myapp W/System.err:     at com.example.myapp.UserInfoActivity.onCreate(:49)
2020-06-23 15:25:51.705 19718-19718/com.example.myapp W/System.err:     at android.app.Activity.performCreate(Activity.java:7955)
2020-06-23 15:25:51.705 19718-19718/com.example.myapp W/System.err:     at android.app.Activity.performCreate(Activity.java:7944)
2020-06-23 15:25:51.705 19718-19718/com.example.myapp W/System.err:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1307)
2020-06-23 15:25:51.705 19718-19718/com.example.myapp W/System.err:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3423)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3595)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2147)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:107)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at android.os.Looper.loop(Looper.java:237)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:7807)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
2020-06-23 15:25:51.706 19718-19718/com.example.myapp W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1047)

Answer 1

So basically, your classes, fields are being renamed during obfuscation hence leading to this error. The easiest way to solve this is to add the full class name of the class you don't wish to be obfuscated in the pro guard rules file. Refer: ProGuard - Obfuscating apk causing error