ERROR ... Cannot invoke "....p25.phase1.message.pdu.PDUSequence.getHeader()" because "this.mPDUSequence" is null

[jaycoastal]

Hi everyone,

Hope all are doing well.

I've just added a fourth NESDR SMArt RTL-SDR v5 USB dongle to one of my systems. I've noticed since then that, rarely in comparison to how busy the system is, yet on a daily basis, I am getting the following error in the log files:

java.lang.NullPointerException: Cannot invoke "io.github.dsheirer.module.decode.p25.phase1.message.pdu.PDUSequence.getHeader()" because "this.mPDUSequence" is null
        at io.github.dsheirer.module.decode.p25.phase1.P25P1MessageFramer.dispatchMessage(P25P1MessageFramer.java:274)
        at io.github.dsheirer.module.decode.p25.phase1.P25P1MessageFramer.receive(P25P1MessageFramer.java:203)
        at io.github.dsheirer.module.decode.p25.phase1.P25P1MessageFramer.receive(P25P1MessageFramer.java:69)
        at io.github.dsheirer.sample.Broadcaster.broadcast(Broadcaster.java:128)
        at io.github.dsheirer.sample.Broadcaster.receive(Broadcaster.java:52)
        at io.github.dsheirer.dsp.psk.PSKDemodulator.broadcast(PSKDemodulator.java:87)
        at io.github.dsheirer.dsp.psk.DQPSKDecisionDirectedDemodulator.calculateSymbol(DQPSKDecisionDirectedDemodulator.java:88)
        at io.github.dsheirer.dsp.psk.PSKDemodulator.receive(PSKDemodulator.java:146)
        at io.github.dsheirer.dsp.psk.PSKDemodulator.receive(PSKDemodulator.java:121)
        at io.github.dsheirer.module.decode.p25.phase1.P25P1DecoderC4FM.receive(P25P1DecoderC4FM.java:124)
        at io.github.dsheirer.module.decode.p25.phase1.P25P1DecoderC4FM.receive(P25P1DecoderC4FM.java:40)
        at io.github.dsheirer.sample.Broadcaster.broadcast(Broadcaster.java:128)
        at io.github.dsheirer.sample.Broadcaster.receive(Broadcaster.java:52)
        at io.github.dsheirer.dsp.filter.channelizer.PolyphaseChannelSource.receive(PolyphaseChannelSource.java:145)
        at io.github.dsheirer.dsp.filter.channelizer.PolyphaseChannelSource.receive(PolyphaseChannelSource.java:40)
        at io.github.dsheirer.dsp.filter.channelizer.output.OneChannelOutputProcessor.process(OneChannelOutputProcessor.java:113)
        at io.github.dsheirer.dsp.filter.channelizer.output.ChannelOutputProcessor.lambda$new$0(ChannelOutputProcessor.java:56)
        at io.github.dsheirer.util.Dispatcher.process(Dispatcher.java:184)
        at io.github.dsheirer.util.Dispatcher$ProcessorWithHeartbeat.run(Dispatcher.java:226)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
        at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source)
        at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.base/java.lang.Thread.run(Unknown Source)```

This isn't a fatal error, but I do wonder what harm it is doing to the system - for example, is it locking up the tuner that caused the error? I use my system headless, and this error occurs randomly, so is not the easiest to check the status of the tuner.

I wonder if this is simply a bug? Should the code be able to handle when mPDUSequence is null? Is it a sign of a bigger issue?

Apart from coming up with a solution to this issue, it'd be handy to have the 'Error while broadcasting ...' message updated to include reference to which tuner was involved.

When I notice this error in the logs, I am shutting down SDRTrunk, and restarting it. Eventually the error reappears though.

Any ideas?

Here's some details of my system:

```SDRTrunk Version  : 0.6.1  [14MB/32MB 43%]
Gradle Version    : Gradle 8.10  [14MB/32MB 43%]
Build Timestamp   : 2024-12-03T16:29:36.848-0500  [14MB/32MB 43%]
Build-JDK         : 23 (BellSoft 23+38  [14MB/32MB 43%]
Build OS          : Linux (amd64 6.8.0-49-generic  [14MB/32MB 43%]
Host OS Name:          Windows 10  [14MB/32MB 43%]
Host OS Arch:          amd64  [14MB/32MB 43%]
Host OS Version:       10.0  [14MB/32MB 43%]
Host CPU Cores:        8  [14MB/32MB 43%]
Host Max Java Memory:  15 GB  [14MB/32MB 43%]```

Thanks in advance!

[DSheirer]

I created an issue for this error. It should not impact the rest of the application.

[jaycoastal]

Thanks. And sorry for my horrible formatting... I just can't get it to format the info the way I intend :(