Recently new crashes in production seemingly from RxFingerprint

[ghost]

Hi, we've been using RxFingerprint for over a year and ne'er once saw a crash. On June 20th, it began crashing frequently (46 times impacting 21 users). Here's the trace:

at io.reactivex.internal.observers.LambdaObserver.a_ (LambdaObserver.java:32)
at io.reactivex.internal.observers.BasicFuseableObserver.a_ (BasicFuseableObserver.java:13)
at io.reactivex.internal.operators.observable.ObservableCreate$CreateEmitter.b (ObservableCreate.java:17)
at io.reactivex.internal.operators.observable.ObservableCreate$CreateEmitter.dispose (ObservableCreate.java)
or .onError (ObservableCreate.java)
or .onNext (ObservableCreate.java)
or .setCancellable (ObservableCreate.java)
or .setDisposable (ObservableCreate.java)
at com.mtramin.rxfingerprint.FingerprintObservable$2.onAuthenticationError (FingerprintObservable.java:15)
at android.hardware.fingerprint.FingerprintManager$MyHandler.sendErrorResult (FingerprintManager.java:1285)
at android.hardware.fingerprint.FingerprintManager$MyHandler.handleMessage (FingerprintManager.java:1230)
at android.os.Handler.dispatchMessage (Handler.java:105)
at android.os.Looper.loop (Looper.java:164)
at android.app.ActivityThread.main (ActivityThread.java:6938)
at java.lang.reflect.Method.invoke (Method.java)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run (Zygote.java:327)
at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1374)

I've verified all usages of RxFingerprint and confirm they all have onError() handlers. Any idea how we can explore this further?