07-23 12:56:12.710 30846-30846/ru.mobiledimension.kbr E/AndroidRuntime: FATAL EXCEPTION: main
    Process: ru.mobiledimension.kbr, PID: 30846
    io.reactivex.exceptions.OnErrorNotImplementedException: Cannot access database on the main thread since it may potentially lock the UI for a long period of time.
        at io.reactivex.internal.functions.Functions$OnErrorMissingConsumer.accept(Functions.java:704)
        at io.reactivex.internal.functions.Functions$OnErrorMissingConsumer.accept(Functions.java:701)
        at io.reactivex.internal.observers.ConsumerSingleObserver.onError(ConsumerSingleObserver.java:47)
        at io.reactivex.internal.operators.single.SingleDoOnError$DoOnError.onError(SingleDoOnError.java:63)
        at io.reactivex.internal.operators.single.SingleDoOnSuccess$DoOnSuccess.onError(SingleDoOnSuccess.java:64)
        at io.reactivex.internal.operators.single.SingleDoOnSubscribe$DoOnSubscribeSingleObserver.onError(SingleDoOnSubscribe.java:86)
        at io.reactivex.internal.operators.single.SingleFlatMap$SingleFlatMapCallback$FlatMapSingleObserver.onError(SingleFlatMap.java:116)
        at io.reactivex.internal.operators.single.SingleFlatMap$SingleFlatMapCallback$FlatMapSingleObserver.onError(SingleFlatMap.java:116)
        at io.reactivex.internal.operators.single.SingleFlatMap$SingleFlatMapCallback$FlatMapSingleObserver.onError(SingleFlatMap.java:116)
        at io.reactivex.internal.operators.single.SingleObserveOn$ObserveOnSingleObserver.run(SingleObserveOn.java:79)
        at io.reactivex.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:109)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:148)
        at android.app.ActivityThread.main(ActivityThread.java:5487)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:765)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:655)
     Caused by: java.lang.IllegalStateException: Cannot access database on the main thread since it may potentially lock the UI for a long period of time.
        at android.arch.persistence.room.RoomDatabase.assertNotMainThread(RoomDatabase.java:204)
        at android.arch.persistence.room.RoomDatabase.query(RoomDatabase.java:232)
        at ru.mobiledimension.kbr.data.daos.MomDao_Impl$6.call(MomDao_Impl.java:218)
        at ru.mobiledimension.kbr.data.daos.MomDao_Impl$6.call(MomDao_Impl.java:215)
        at io.reactivex.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:35)
        at io.reactivex.Single.subscribe(Single.java:2779)
        at io.reactivex.internal.operators.single.SingleDoOnError.subscribeActual(SingleDoOnError.java:35)
        at io.reactivex.Single.subscribe(Single.java:2779)
        at io.reactivex.internal.operators.single.SingleObserveOn.subscribeActual(SingleObserveOn.java:35)
        at io.reactivex.Single.subscribe(Single.java:2779)
        at io.reactivex.internal.operators.single.SingleFlatMap$SingleFlatMapCallback.onSuccess(SingleFlatMap.java:84)
        at io.reactivex.internal.operators.single.SingleFlatMap$SingleFlatMapCallback$FlatMapSingleObserver.onSuccess(SingleFlatMap.java:111)
        at io.reactivex.internal.operators.single.SingleObserveOn$ObserveOnSingleObserver.run(SingleObserveOn.java:81)
        at io.reactivex.android.schedulers.HandlerScheduler$ScheduledRunnable.run(HandlerScheduler.java:109)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:148)
        at android.app.ActivityThread.main(ActivityThread.java:5487)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:765)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:655)