NullReferenceException: mono-3.6.0

[Mirabis]

A few days ago I started having crashes shortly after starting nzbdrone.

Running debug gave me:

EPIC FAIL: System.NullReferenceException: Object reference not set to an instance of an object
  at System.Threading.EventWaitHandle.Reset () [0x00012] in /root/mono-3.6.0/mcs/class/corlib/System.Threading/E                                     ventWaitHandle.cs:198
  at (wrapper remoting-invoke-with-check) System.Threading.EventWaitHandle:Reset ()
  at System.Threading.Timer+Scheduler.SchedulerThread () [0x0002f] in /root/mono-3.6.0/mcs/class/corlib/System.T                                     hreading/Timer.cs:328
  at System.Threading.Thread.StartInternal () [0x00016] in /root/mono-3.6.0/mcs/class/corlib/System.Threading/Th                                     read.cs:691
[Fatal] GlobalExceptionHandlers: EPIC FAIL: Object reference not set to an instance of an object

System.NullReferenceException: Object reference not set to an instance of an object
  at System.Threading.EventWaitHandle.Reset () [0x00012] in /root/mono-3.6.0/mcs/class/corlib/System.Threading/E                                     ventWaitHandle.cs:198
  at (wrapper remoting-invoke-with-check) System.Threading.EventWaitHandle:Reset ()
  at System.Threading.Timer+Scheduler.SchedulerThread () [0x0002f] in /root/mono-3.6.0/mcs/class/corlib/System.T                                     hreading/Timer.cs:328
  at System.Threading.Thread.StartInternal () [0x00016] in /root/mono-3.6.0/mcs/class/corlib/System.Threading/Th                                     read.cs:691

Stacktrace:


Native stacktrace:

        mono() [0x4b5586]
        mono() [0x50e0a3]
        mono() [0x423e90]
        /lib/x86_64-linux-gnu/libpthread.so.0(+0xf8d0) [0x7efee4ea18d0]
        [0x41b16a21]

Debug info from gdb:


=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================

Aborted

[Mirabis]

Upgraded mono to 3.10 - still receive SIGSEGV

root@DownloadServer:~# mono --debug /opt/NzbDrone/NzbDrone.exe
[Info] Bootstrap: Starting Sonarr - /opt/NzbDrone/NzbDrone.exe - Version 2.0.0.3                                                                                          243
[Debug] ProcessProvider: Found 0 processes with the name: NzbDrone.Console
[Debug] ProcessProvider: Found 1 processes with the name: NzbDrone
[Info] MigrationLogger: *** Migrating data source=/root/.config/NzbDrone/nzbdron                                                                                          e.db;cache size=-10485760;datetimekind=Utc;journal mode=Wal;pooling=True;version                                                                                          =3 ***
[Debug] MigrationLogger: Took: 00:00:00.1263737
[Info] MigrationLogger: *** Migrating data source=/root/.config/NzbDrone/logs.db                                                                                          ;cache size=-10485760;datetimekind=Utc;journal mode=Wal;pooling=True;version=3 *                                                                                          **
[Debug] MigrationLogger: Took: 00:00:00.0065111
[Info] Router: Application mode: Interactive
[Debug] Router: Console selected
[Info] OwinHostController: Listening on the following URLs:
[Info] OwinHostController:   http://*:8082/nzbdrone/
[Info] OwinHostController:   http://*:8082/
[Debug] OwinAppFactory: Attaching NzbDroneVersionMiddleWare to host
[Debug] OwinAppFactory: Attaching SignalRMiddleWare to host
[Debug] OwinAppFactory: Attaching NancyMiddleWare to host
[Info] NancyBootstrapper: Starting NzbDrone API
[Trace] EventAggregator: Publishing ApplicationStartedEvent
[Trace] EventAggregator: ApplicationStartedEvent -> UserService
[Trace] EventAggregator: ApplicationStartedEvent <- UserService
[Trace] EventAggregator: ApplicationStartedEvent -> DownloadClientFactory
[Debug] DownloadClientFactory: Initializing Providers. Count 8
[Trace] EventAggregator: ApplicationStartedEvent <- DownloadClientFactory
[Trace] EventAggregator: ApplicationStartedEvent -> IndexerFactory
[Debug] IndexerFactory: Initializing Providers. Count 12
EPIC FAIL: System.NullReferenceException: Object reference not set to an instanc                                                                                          e of an object
  at System.Threading.Timer+Scheduler.SchedulerThread () [0x00000] in <filename                                                                                           unknown>:0
  at System.Threading.Thread.StartInternal () [0x00000] in <filename unknown>:0
[Fatal] GlobalExceptionHandlers: EPIC FAIL: Object reference not set to an insta                                                                                          nce of an object

System.NullReferenceException: Object reference not set to an instance of an obj                                                                                          ect
  at System.Threading.Timer+Scheduler.SchedulerThread () [0x00000] in <filename                                                                                           unknown>:0
  at System.Threading.Thread.StartInternal () [0x00000] in <filename unknown>:0

[Trace] EventAggregator: ApplicationStartedEvent <- IndexerFactory
[Trace] EventAggregator: ApplicationStartedEvent -> ReconfigureLogging
[ERROR] FATAL UNHANDLED EXCEPTION: System.NullReferenceException: Object referen                                                                                          ce not set to an instance of an object
  at System.Threading.Timer+Scheduler.SchedulerThread () [0x00000] in <filename                                                                                           unknown>:0
  at System.Threading.Thread.StartInternal () [0x00000] in <filename unknown>:0

[markus101]

Native mono crashes [kernel fix released]

“For every action there is an equal and opposite reaction.” We’ve had quite a few reports about odd crashes, most of them known to be so called Native crashes, where mono cries out in terror and dies without telling us why. Initially this thread was to collect important information about the systems on which the crashes occurred. Since this thread was posted I’ve literally spent more than a hundred hours investigating this issue. Debugging Sonarr and mono countless times, compiled mono half …

[Mirabis]

Was aware of the kernel issues and had previously upgraded the kernel which fixed it… but suddenly it came back hmm

[markus101]

Which kernel are you running now?

[Mirabis]

Linux version 3.16.0-4-amd64 (debian-kernel@lists.debian.org) (gcc version 4.8.4 (Debian 4.8.4-1) ) #1 SMP Debian 3.16.7-ckt9-3~deb8u1 (2015-04-24)

[Mirabis]

Running Linux version 4.0.0-1-amd64 // 4.0.2-1 (2015-05-11) now to test

[markus101]

Looks like it was fixed in: Fixed in versions linux/4.0.2-1, linux/3.16.7-ckt11-1 Not 100% sure what the numbers after ckt mean, but to me that indicates its older than the fix in version. The bug wasn’t closed until the 25th of May, around the time it went public (two weeks after that May 11th release).