error - NullPointerException Traccar 5.9

I recently upgraded to version 5.9 of Traccar and I have detected that I am getting the error
error - NullPointerException
Attached imagehttps://ibb.co/Nrtr8Gp

I checked in the forum and found other similar cases but where you can detect the problem more easily, but in this case I do not know why the error occurs.

any suggestions?

Surely the real HEX from the log will be requested.

Try enabling full stack traces to see more details about the error.

Ok, do that and I'll share the results

this is an extract from the log file

2023-12-14 21:12:36  INFO: [T6a89ee80: gl200 < 186.11.61.127] 2b524553503a47544652492c3530303130312c3836383537343034303338363430362c2c31343436382c31312c312c312c31342e342c3134322c3139372e322c2d37322e3433383536302c2d33382e3534303931302c32303233313231353030303932392c303733302c303030312c373835352c333839373733412c30302c302e302c2c2c2c3130302c3232303130302c2c2c2c32303233313231353030303933302c3637373324
2023-12-14 21:12:37  INFO: [Te066cd12: gl200 < 186.11.24.48] 2b524553503a47544652492c3530303130312c3836383537343034303433363934362c2c31343332302c31312c312c312c332e322c322c3339362e372c2d37322e3131323132302c2d33382e3636353137382c32303233313231353030313235362c2c2c2c2c30302c302e302c2c2c2c3130302c3232303130302c2c2c2c32303233313231353030313235362c4342334424
2023-12-14 21:12:37  INFO: [Te066cd12] id: 868574040xxxxxx, time: 2023-12-14 21:12:56, lat: -38.66518, lon: -72.11212, speed: 1.7, course: 2.0
2023-12-14 21:12:37  INFO: [T6a89ee80] error - 
java.lang.NullPointerException: Cannot invoke "String.getBytes()" because the return value of "org.traccar.config.Config.getString(org.traccar.config.ConfigKey)" is null
    at org.traccar.notificators.NotificatorFirebase.<init>(NotificatorFirebase.java:76)
    at org.traccar.notificators.NotificatorFirebase$$FastClassByGuice$$13dbfd71.GUICE$TRAMPOLINE(<generated>)
    at org.traccar.notificators.NotificatorFirebase$$FastClassByGuice$$13dbfd71.apply(<generated>)
    at com.google.inject.internal.DefaultConstructionProxyFactory$FastClassProxy.newInstance(DefaultConstructionProxyFactory.java:82)
    at com.google.inject.internal.ConstructorInjector.provision(ConstructorInjector.java:114)
    at com.google.inject.internal.ConstructorInjector.construct(ConstructorInjector.java:91)
    at com.google.inject.internal.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:300)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.internal.SingletonScope$1.get(SingletonScope.java:169)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:45)
    at com.google.inject.internal.InjectorImpl$1.get(InjectorImpl.java:1148)
    at com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1186)
    at org.traccar.notification.NotificatorManager.getNotificator(NotificatorManager.java:70)
    at org.traccar.database.NotificationManager.lambda$updateEvent$3(NotificationManager.java:110)
    at java.base/java.lang.Iterable.forEach(Iterable.java:75)
    at org.traccar.database.NotificationManager.lambda$updateEvent$4(NotificationManager.java:107)
    at java.base/java.lang.Iterable.forEach(Iterable.java:75)
    at org.traccar.database.NotificationManager.updateEvent(NotificationManager.java:106)
    at org.traccar.database.NotificationManager.updateEvents(NotificationManager.java:148)
    at org.traccar.handler.events.BaseEventHandler.handlePosition(BaseEventHandler.java:40)
    at org.traccar.BaseDataHandler.channelRead(BaseDataHandler.java:27)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
...
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562)
    at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
    at java.base/java.lang.Thread.run(Thread.java:833)

2023-12-14 21:12:37  INFO: [T6a89ee80] disconnected

Looks like you misconfigured something. Specifically Firebase configuration is missing.

Thank you very much Anton, in the process of upgrading to version 5.9 I forgot to configure WhatsApp notifications correctly.

Hi Cristian, If you got whatsapp working correctly you might reply here.

https://www.traccar.org/forums/topic/whatsapp-notifications-instead-of-telegram/#post-92297

actually the correct answer was that I had not configured push notifications properly (firebase).
But you can also have WhatsApp notifications in Traccar.