java.lang.NoClassDefFoundError in Android 9 asynctask

Question

I just published a new version of our app to the Play store and I am suddenly getting a ton of java.lang.NoClassDefFoundError exceptions. They seem to be only for Android 9. Here is the stack trace..any ideas?

I can't seem to replicate it in the debugger.

java.lang.RuntimeException: 
  at android.os.AsyncTask$3.done (AsyncTask.java:354)
  at java.util.concurrent.FutureTask.finishCompletion (FutureTask.java:383)
  at java.util.concurrent.FutureTask.setException (FutureTask.java:252)
  at java.util.concurrent.FutureTask.run (FutureTask.java:271)
  at android.os.AsyncTask$SerialExecutor$1.run (AsyncTask.java:245)
  at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1167)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:641)
  at java.lang.Thread.run (Thread.java:764)
Caused by: java.lang.NoClassDefFoundError: 
  at com.concept2.ergdata.Sync2.getUser (Sync2.java:304)
  at com.concept2.ergdata.Sync2.synchronize (Sync2.java:76)
  at com.concept2.ergdata.ErgData$synchronize.doInBackground (ErgData.java:2284)
  at com.concept2.ergdata.ErgData$synchronize.doInBackground (ErgData.java:2281)
  at android.os.AsyncTask$2.call (AsyncTask.java:333)
  at java.util.concurrent.FutureTask.run (FutureTask.java:266)
Caused by: java.lang.ClassNotFoundException: 
  at dalvik.system.BaseDexClassLoader.findClass (BaseDexClassLoader.java:169)
  at java.lang.ClassLoader.loadClass (ClassLoader.java:379)
  at java.lang.ClassLoader.loadClass (ClassLoader.java:312)

Answer 1

java reflection was limited in android 9 ,for more details please check android site