# system/IO-TCP/selectors msg was not delivered ! akka 2.5.19

**URL:** <https://discuss.akka.io/t/system-io-tcp-selectors-msg-was-not-delivered-akka-2-5-19/3072>\
**Category:** Akka Libraries\
**Tags:** akka-cluster\
**Created:** [January 4, 2019, 6:18am UTC](https://discuss.akka.io/t/system-io-tcp-selectors-msg-was-not-delivered-akka-2-5-19/3072 "2019-01-04T06:18:10Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![TopSpoofer](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.akka.io/topspoofer/32/955_2.png) [@TopSpoofer](https://discuss.akka.io/u/TopSpoofer)\
**Post date:** [January 4, 2019, 6:18am UTC](https://discuss.akka.io/t/system-io-tcp-selectors-msg-was-not-delivered-akka-2-5-19/3072/1 "2019-01-04T06:18:10Z")

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Message [akka.io.TcpConnection$Unregistered$] from Actor[akka://sms/system/IO-TCP/selectors/$a/4#-1951800158] to Actor[akka://sms/system/IO-TCP/selectors/$a/4#-1951800158] was not delivered. [1] dead letters encountered. If this is not an expected behavior, then [Actor[akka://sms/system/IO-TCP/selectors/$a/4#-1951800158]] may have terminated unexpectedly, This logging can be turned off or adjusted with configuration settings ‘akka.log-dead-letters’ and ‘akka.log-dead-letters-during-shutdown’.

akka 2.5.19

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**Author:** ![countfloyd](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.akka.io/countfloyd/32/309_2.png) [@countfloyd](https://discuss.akka.io/u/countfloyd)\
**Post date:** [January 16, 2019, 11:30pm UTC](https://discuss.akka.io/t/system-io-tcp-selectors-msg-was-not-delivered-akka-2-5-19/3072/2 "2019-01-16T23:30:42Z")

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Just started seeing this as well. Did you figure out the issue?

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**Author:** ![johanandren](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.akka.io/johanandren/32/85_2.png) [@johanandren](https://discuss.akka.io/u/johanandren)\
**Post date:** [January 17, 2019, 7:20am UTC](https://discuss.akka.io/t/system-io-tcp-selectors-msg-was-not-delivered-akka-2-5-19/3072/3 "2019-01-17T07:20:28Z")

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More details about during what circumstances you see these would be good, is it using the TCP streams, remoting, Akka IO directly, client/server etc?