[BUG] App crashes and shows offline

[jontok]

[BUG] App crashes and shows offline

I have recently setup a Grocy instance via the linuxserver.io docker image, after installing the app and scanning the API Key QR code the app either shows "Not a Valid Grocy instance" or opens the Overview but Showing "Offline"

I had a connection to the server at some point, but after trying to add a product to the Shopping list the app crashed and showed the same error.

Device

Google Pixel 4a 5G

App Version: 3.8.1
Grocy Version 4.4.2

Steps to reproduce

• clear cache and storage for the App
• open the app and configure you own server
• scan QR code

Hosting

Docker Compose

---
services:
  grocy:
    image: lscr.io/linuxserver/grocy:latest
    container_name: grocy
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Etc/UTC
    volumes:
      - /path/to/grocy/config:/config
    ports:
      - 9283:80
    restart: unless-stopped

Caddy Reverse Proxy

my.domain.tld {
        reverse_proxy 127.0.0.1:9283 
        encode gzip zstd
        log {
                output file /var/log/caddy/access.log
        } 
}

Error

Error: End of input at character 0 of 

org.json.JSONException: End of input at character 0 of 
	at org.json.JSONTokener.syntaxError(JSONTokener.java:469)
	at org.json.JSONTokener.nextValue(JSONTokener.java:101)
	at org.json.JSONObject.<init>(JSONObject.java:168)
	at org.json.JSONObject.<init>(JSONObject.java:185)
	at xyz.zedler.patrick.grocy.helper.DownloadHelper$$ExternalSyntheticLambda8.onResponse(R8$$SyntheticClass:10)
	at xyz.zedler.patrick.grocy.model.Location$3$$ExternalSyntheticLambda1.onResponse(R8$$SyntheticClass:1)
	at xyz.zedler.patrick.grocy.web.CustomStringRequest$$ExternalSyntheticLambda0.onResponse(R8$$SyntheticClass:17)
	at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:11)
	at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:27)
	at android.os.Handler.handleCallback(Handler.java:959)
	at android.os.Handler.dispatchMessage(Handler.java:100)
	at android.os.Looper.loopOnce(Looper.java:232)
	at android.os.Looper.loop(Looper.java:317)
	at android.app.ActivityThread.main(ActivityThread.java:8592)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:580)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:878)

Grocy Logcat

Grocy Logcat

--------- beginning of crash
03-22 15:42:31.147  5247  5474 E AndroidRuntime: FATAL EXCEPTION: RxCachedThreadScheduler-2
03-22 15:42:31.147  5247  5474 E AndroidRuntime: Process: xyz.zedler.patrick.grocy, PID: 5247
03-22 15:42:31.147  5247  5474 E AndroidRuntime: java.lang.NullPointerException: Parameter specified as non-null is null: method androidx.room.EntityInsertionAdapter.insertAndReturnIdsList, parameter entities
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at androidx.room.EntityInsertionAdapter.insertAndReturnIdsList(Unknown Source:2)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at xyz.zedler.patrick.grocy.dao.StockItemDao_Impl$3.call(StockItemDao_Impl.java:52)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:20)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.subscribe(Single.java:5)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.blockingSubscribe(Single.java:7)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at xyz.zedler.patrick.grocy.model.StockItem$2$$ExternalSyntheticLambda2.call(R8$$SyntheticClass:28)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:20)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.subscribe(Single.java:5)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleSubscribeOn$SubscribeOnObserver.run(SingleSubscribeOn.java:3)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Scheduler$DisposeTask.run(Scheduler.java:10)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:22)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:1)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at java.util.concurrent.FutureTask.run(FutureTask.java:264)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:307)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
03-22 15:42:31.147  5247  5474 E AndroidRuntime: 	at java.lang.Thread.run(Thread.java:1012)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: FATAL EXCEPTION: RxCachedThreadScheduler-4
03-22 15:53:48.469  9654 10413 E AndroidRuntime: Process: xyz.zedler.patrick.grocy, PID: 9654
03-22 15:53:48.469  9654 10413 E AndroidRuntime: java.lang.NullPointerException: Parameter specified as non-null is null: method androidx.room.EntityInsertionAdapter.insertAndReturnIdsList, parameter entities
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at androidx.room.EntityInsertionAdapter.insertAndReturnIdsList(Unknown Source:2)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at xyz.zedler.patrick.grocy.dao.RecipeDao_Impl$3.call(RecipeDao_Impl.java:52)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:20)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.subscribe(Single.java:5)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.blockingSubscribe(Single.java:7)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at xyz.zedler.patrick.grocy.model.Recipe$2$$ExternalSyntheticLambda2.call(R8$$SyntheticClass:83)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:20)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.subscribe(Single.java:5)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleSubscribeOn$SubscribeOnObserver.run(SingleSubscribeOn.java:3)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Scheduler$DisposeTask.run(Scheduler.java:10)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:22)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:1)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at java.util.concurrent.FutureTask.run(FutureTask.java:264)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:307)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
03-22 15:53:48.469  9654 10413 E AndroidRuntime: 	at java.lang.Thread.run(Thread.java:1012)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: FATAL EXCEPTION: RxCachedThreadScheduler-1
03-22 15:53:58.556 10428 10463 E AndroidRuntime: Process: xyz.zedler.patrick.grocy, PID: 10428
03-22 15:53:58.556 10428 10463 E AndroidRuntime: java.lang.NullPointerException: Parameter specified as non-null is null: method androidx.room.EntityInsertionAdapter.insertAndReturnIdsList, parameter entities
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at androidx.room.EntityInsertionAdapter.insertAndReturnIdsList(Unknown Source:2)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at xyz.zedler.patrick.grocy.dao.RecipeDao_Impl$3.call(RecipeDao_Impl.java:52)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:20)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.subscribe(Single.java:5)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.blockingSubscribe(Single.java:7)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at xyz.zedler.patrick.grocy.model.Recipe$2$$ExternalSyntheticLambda2.call(R8$$SyntheticClass:83)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:20)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.subscribe(Single.java:5)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleSubscribeOn$SubscribeOnObserver.run(SingleSubscribeOn.java:3)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Scheduler$DisposeTask.run(Scheduler.java:10)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:22)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:1)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at java.util.concurrent.FutureTask.run(FutureTask.java:264)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:307)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
03-22 15:53:58.556 10428 10463 E AndroidRuntime: 	at java.lang.Thread.run(Thread.java:1012)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: FATAL EXCEPTION: RxCachedThreadScheduler-1
03-22 15:54:35.247 10596 10623 E AndroidRuntime: Process: xyz.zedler.patrick.grocy, PID: 10596
03-22 15:54:35.247 10596 10623 E AndroidRuntime: java.lang.NullPointerException: Parameter specified as non-null is null: method androidx.room.EntityInsertionAdapter.insertAndReturnIdsList, parameter entities
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at androidx.room.EntityInsertionAdapter.insertAndReturnIdsList(Unknown Source:2)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at xyz.zedler.patrick.grocy.dao.RecipeDao_Impl$3.call(RecipeDao_Impl.java:52)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:20)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.subscribe(Single.java:5)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.blockingSubscribe(Single.java:7)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at xyz.zedler.patrick.grocy.model.Recipe$2$$ExternalSyntheticLambda2.call(R8$$SyntheticClass:83)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleFromCallable.subscribeActual(SingleFromCallable.java:20)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Single.subscribe(Single.java:5)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.operators.single.SingleSubscribeOn$SubscribeOnObserver.run(SingleSubscribeOn.java:3)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.core.Scheduler$DisposeTask.run(Scheduler.java:10)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:22)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:1)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at java.util.concurrent.FutureTask.run(FutureTask.java:264)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:307)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
03-22 15:54:35.247 10596 10623 E AndroidRuntime: 	at java.lang.Thread.run(Thread.java:1012)
--------- beginning of main
03-22 15:54:37.658 10783 10783 E r.patrick.grocy: Not starting debugger since process cannot load the jdwp agent.
03-22 15:54:38.039 10783 10783 E ConfigUtil: downloadSystemInfo: org.json.JSONException: End of input at character 0 of 
03-22 15:54:38.138 10783 10783 E OverviewStartViewModel: getTimeDbChanged: org.json.JSONException: End of input at character 0 of 
03-22 16:00:17.037 11444 11444 E r.patrick.grocy: Not starting debugger since process cannot load the jdwp agent.
03-22 16:00:17.221 11444 11444 E TextView: Saved cursor position 3346/3346 out of range for text

[Z-ack-L]

App doesn't crash but keeps showing offline on my phone.
I found the possible solution: change MTU to 1500.

Env

linuxserver.io's Grocy docker 4.4.2
grocy-android 3.8.1

Details

My home network topology is: cell phone - router WLAN - router LAN - raspberry pi (grocy server)
My router MTU is: 1492 for LAN, 1492 for WAN and 1500 for WLAN.

In this condition, PC on LAN (WIndows network connection config MTU is 1500) can open grocy normally, phone on WLAN can open grocy normally.

If the MTU of the WLAN is not 1500, grocy on the phone grocy-android and grocy-mobile and the browser will not open grocy.

I only have a basic knowledge of MTU and I'm not sure why my PC's browser works fine with Grocy, but it looks like it's an MTU issue.

[Saturo78]

Same here. Most of the time offline or network error, while accessing grocy via webbrowser works fine.