Today kopano-gateway crashed on my ubuntu 18.04 server (x86_64)
I am running core-8.6.81.24_0+4-Ubuntu_18.04-amd64.tar.gz

Here is the backtrace of the error:

Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: ----------------------------------------------------------------------
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Fatal error detected. Please report all following information.
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Application kopano-gateway version: 8.6.81
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: OS: Linux, release: 4.15.0-33-generic, version: #36-Ubuntu SMP Wed Aug 15 16:00:05 UTC 2018, hardware: x86_64
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Thread name: NotifyThread
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Peak RSS: 127928
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Pid 817 caught SIGABRT (6), out of memory or unhandled exception, traceback:
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Backtrace:
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #0. /usr/lib/x86_64-linux-gnu/libkcutil.so.0(+0x45a90) [0x7fc39f25aa90]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #1. /usr/lib/x86_64-linux-gnu/libkcutil.so.0(+0x34f2d) [0x7fc39f249f2d]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #2. /usr/lib/x86_64-linux-gnu/libkcutil.so.0(_ZN2KC23generic_sigsegv_handlerEPNS_8ECLoggerEPKcS3_iPK9siginfo_tPKv+0x19f) [0x7fc39f24a1df]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #3. /lib/x86_64-linux-gnu/libpthread.so.0(+0x12890) [0x7fc39f008890]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #4. /lib/x86_64-linux-gnu/libc.so.6(gsignal+0xc7) [0x7fc39e2e6e97]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #5. /lib/x86_64-linux-gnu/libc.so.6(abort+0x141) [0x7fc39e2e8801]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #6. /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0x8c8fb) [0x7fc39e93d8fb]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #7. /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0x92d3a) [0x7fc39e943d3a]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #8. /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0x92d95) [0x7fc39e943d95]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #9. /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0x92fe8) [0x7fc39e943fe8]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #10. /usr/sbin/kopano-gateway(+0x11b0f) [0x5556e731fb0f]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #11. /usr/sbin/kopano-gateway(+0x2e94c) [0x5556e733c94c]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #12. /usr/lib/x86_64-linux-gnu/kopano/libkcclient.so(+0xb4e4f) [0x7fc397dcee4f]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #13. /usr/lib/x86_64-linux-gnu/kopano/libkcclient.so(+0xb84ae) [0x7fc397dd24ae]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #14. /lib/x86_64-linux-gnu/libpthread.so.0(+0x76db) [0x7fc39effd6db]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: #15. /lib/x86_64-linux-gnu/libc.so.6(clone+0x3f) [0x7fc39e3c988f]
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Signal errno: Success, signal code: -6
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Sender pid: 817, sender uid: 999, si_status: 0
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: Signal value: 0, faulting address: 0x3e700000331
Aug 28 14:38:56 <name_of_server> kopano-gateway[817]: When reporting this traceback, please include Linux distribution name (and version), system architecture and Kopano version.