Java API failure after Proguard handling

Hi,

I am experiencing difficulties on Java API. My android app is working normally when Proguard setting "minifiEnabled" is set to false, but will be malfunction if set to true. The following log is the related detail.

06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err: java.util.concurrent.ExecutionException: com.dropbox.core.BadRequestException: Error in call to API function "users/get_current_account": Invalid authorization value in HTTP header "Authorization": "Bearer".  Expecting "Bearer <oauth2-access-token>".
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at java.util.concurrent.FutureTask.report(FutureTask.java:94)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at java.util.concurrent.FutureTask.get(FutureTask.java:164)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at hk.com.fgoproduction.getdroplets.Lib.Common.ThisApplication.runOnBgAndJoin(ThisApplication.kt:58)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at hk.com.fgoproduction.getdroplets.Activity.MainActivity.threadExec(MainActivity.kt:187)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at hk.com.fgoproduction.getdroplets.Activity.MainActivity.dropboxStatus(MainActivity.kt:176)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at hk.com.fgoproduction.getdroplets.Activity.MainActivity.testAccessToken(MainActivity.kt:61)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at hk.com.fgoproduction.getdroplets.Activity.MainActivity.onCreate(MainActivity.kt:43)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.app.Activity.performCreate(Activity.java:6237)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.app.ActivityThread.-wrap11(ActivityThread.java)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.os.Looper.loop(Looper.java:148)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5417)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
06-15 10:05:00.623 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err: Caused by: com.dropbox.core.BadRequestException: Error in call to API function "users/get_current_account": Invalid authorization value in HTTP header "Authorization": "Bearer".  Expecting "Bearer <oauth2-access-token>".
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at com.dropbox.core.DbxRequestUtil.unexpectedStatus(DbxRequestUtil.java:285)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at com.dropbox.core.v2.DbxRawClientV2$1.execute(DbxRawClientV2.java:107)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at com.dropbox.core.v2.DbxRawClientV2.executeRetriable(DbxRawClientV2.java:252)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at com.dropbox.core.v2.DbxRawClientV2.rpcStyle(DbxRawClientV2.java:97)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at com.dropbox.core.v2.users.DbxUserUsersRequests.getCurrentAccount(DbxUserUsersRequests.java:120)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at hk.com.fgoproduction.getdroplets.DropboxAPI.AFile.isDropboxOk(AFile.kt:139)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at hk.com.fgoproduction.getdroplets.Activity.MainActivity$dropboxStatus$1.run(MainActivity.kt:176)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:423)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at java.util.concurrent.FutureTask.run(FutureTask.java:237)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
06-15 10:05:00.624 2823-2823/hk.com.fgoproduction.getdroplets W/System.err:     at java.lang.Thread.run(Thread.java:818)

 

And the proguard-rules.pro is at the bottom

-dontobfuscate
-optimizationpasses 5
-dontpreverify
-optimizations !code/simplification/cast,!field/*,!class/merging/*

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Appliction
-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.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class * extends android.view.View
-keep public class com.android.vending.licensing.ILicensingService
-keep class android.support.** {*;}

-keep class com.dropbox.** {*;}
-dontwarn com.dropbox.**

-keep class com.alibaba.fastjson.** {*;}
-dontwarn com.alibaba.fastjson.**

-dontwarn okhttp3.**
-dontwarn com.squareup.okhttp.**
-dontwarn com.google.appengine.**
-dontwarn javax.servlet.**

-keepattributes Signature
-keepattributes SourceFile,LineNumberTable

 

Does anyone have idea on this? It's a disaster that proguard could not be used as the app could not be published.