# How to rotate KES by the official documentation? And where are the official docs on how to rotate KES?

**URL:** <https://forum.cardano.org/t/how-to-rotate-kes-by-the-official-documentation-and-where-are-the-official-docs-on-how-to-rotate-kes/76994>\
**Category:** Operate a Stake Pool\
**Created:** [28 September 2021 12:38 UTC](https://forum.cardano.org/t/how-to-rotate-kes-by-the-official-documentation-and-where-are-the-official-docs-on-how-to-rotate-kes/76994 "2021-09-28T12:38:03Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![maciejso](https://avatars.discourse-cdn.com/v4/letter/m/48db29/32.png) [@maciejso](https://forum.cardano.org/u/maciejso)\
**Post date:** [28 September 2021 12:38 UTC](https://forum.cardano.org/t/how-to-rotate-kes-by-the-official-documentation-and-where-are-the-official-docs-on-how-to-rotate-kes/76994/1 "2021-09-28T12:38:03Z")

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Have just lost another block due to invalid KES signature - something that is supposed to be super trivial but apparently this tech is yet to be tamed. It is literally beyond me why `cardano-node` is incapable of telling whether or not the the KES is valid before it gets selected as a slot leader.

InvalidKesSignatureOCERT

> Sep 28 02:32:44 wladyslawa bash[1480600]: [wladysla:cardano.node.Forge:Error:141] [2021-09-28 01:32:44.03 UTC] fromList [(“val”,Object (fromList [(“kind”,String “TraceForgedInvalidBlock”),(“reason”,Object (fromList [(“error”,Object (fromList [(“error”,Object (fromList [(“failures”,Array [Object (fromList [(“error”,String “Reject”),(“kind”,String “InvalidKesSignatureOCERT”),(“opCertExpectedKESEvolutions”,String “1”),(“opCertKESCurrentPeriod”,String “318”),(“opCertKESStartPeriod”,String “317”)])]),(“kind”,String “ChainTransitionError”)])),(“kind”,String “HeaderProtocolError”)])),(“kind”,String “ValidationError”)])),(“slot”,Number 4.1226473e7)])),(“credentials”,String “Cardano”)]

![Screenshot from 2021-09-28 08-18-25](https://us1.discourse-cdn.com/flex023/uploads/cardano/original/3X/5/b/5be7f3928946983894c21c1afc713475d8f00299.png)  
 ![Screenshot from 2021-09-28 08-58-24](https://us1.discourse-cdn.com/flex023/uploads/cardano/original/3X/c/e/ce2c94d7f4598668c57b875cf51e45647dc92110.png)  
 ![Screenshot from 2021-09-28 09-28-09](https://us1.discourse-cdn.com/flex023/uploads/cardano/original/3X/9/7/971846ddfabcc1a0d9f1583ab74bce71c3d710ff.png)

 ![IMG_20210928_133053](https://us1.discourse-cdn.com/flex023/uploads/cardano/original/3X/3/f/3f71b61079aae61894dcbea77adc9446094ea83c.jpeg)