Crash: NumberFormatException on insertion into Database

[padyx]

Crash report from google play

Galaxy S3 (m0), Android 4.3. Occurrences: 1

#!java

java.lang.RuntimeException: An error occured while executing doInBackground()
at android.support.v4.content.ModernAsyncTask$3.done(ModernAsyncTask.java:137)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
at java.util.concurrent.FutureTask.run(FutureTask.java:239)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NumberFormatException: Invalid long: "null"
at java.lang.Long.invalidLong(Long.java:125)
at java.lang.Long.parseLong(Long.java:342)
at java.lang.Long.parseLong(Long.java:319)
at java.lang.Long.valueOf(Long.java:477)
at ch.defiant.purplesky.services.MessageService.insertMessages(MessageService.java:196)
at ch.defiant.purplesky.services.MessageService.getNewMessagesFromUser(MessageService.java:170)
at ch.defiant.purplesky.loaders.message.EmptyOnlineLoader.loadInBackground(EmptyOnlineLoader.java:33)
at ch.defiant.purplesky.loaders.message.EmptyOnlineLoader.loadInBackground(EmptyOnlineLoader.java:1)
at android.support.v4.content.AsyncTaskLoader.onLoadInBackground(AsyncTaskLoader.java:242)
at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:51)
at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:40)
at android.support.v4.content.ModernAsyncTask$2.call(ModernAsyncTask.java:123)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
... 3 more