Upgraded from ES2.3.5 to 2.4.0, seeing: Transport response handler not found of id

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I'm having the issue on 2.4.1:

[2016-10-07 01:05:47,278][INFO ][node                     ] [irony] version[2.4.1], pid[82019], build[c67dc32/2016-09-27T18:57:55Z]
...
[2016-10-07 13:24:24,506][WARN ][transport                ] [irony] Transport response handler not found of id [68647]
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Can somebody Confirm, this issue is resolved in 2.4.1 ?

Also, is that easy to upgrade 2.4.0 to 2.4.1 ?? Is that a complex process?