I'm currently using the TCP output of NXLog (v2.9.1347) to ship Windows Server 2008 R2 eventlogs to Logstash (v1.4.2) in JSON format; lately I found that NXLog crashes if Logstash has been unavailable for some time and then became available, although it ships a few logs before crashing.

This event is logged in the eventlog:

Faulting application name: nxlog.exe, version: 0.0.0.0, time stamp: 0x54fedd1a
Faulting module name: ntdll.dll, version: 6.1.7601.18247, time stamp: 0x521ea8e7
Exception code: 0xc0000005
Fault offset: 0x0005e8d1
Faulting process id: 0x4e4
Faulting application start time: 0x01d0a2b5080df49c
Faulting application path: C:\Program Files (x86)\nxlog\nxlog.exe
Faulting module path: C:\Windows\SysWOW64\ntdll.dll
Report Id: 7ebdb4d7-1036-11e5-909f-005056a30012

To reproduce the issue, just have NXLog ship logs to Logstash and then stop Logstash for about an hour then start it, NXLog crashes soon after.

Any idea what might be causing this?