# Error: unknown flag: --fleet-server-client-auth

**URL:** <https://discuss.elastic.co/t/error-unknown-flag-fleet-server-client-auth/364778>\
**Category:** Elastic Agent\
**Tags:** fleet\
**Created:** [August 12, 2024, 1:27pm UTC](https://discuss.elastic.co/t/error-unknown-flag-fleet-server-client-auth/364778 "2024-08-12T13:27:07Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![kirolosmena299](https://avatars.discourse-cdn.com/v4/letter/k/e0b2c6/32.png) [@kirolosmena299](https://discuss.elastic.co/u/kirolosmena299)\
**Post date:** [August 12, 2024, 1:27pm UTC](https://discuss.elastic.co/t/error-unknown-flag-fleet-server-client-auth/364778/1 "2024-08-12T13:27:07Z")

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I have a problem whenever i try to install the agent to some of my Ubuntu servers I get this error :  
Error: unknown flag: --fleet-server-client-auth

 ![elk](https://us1.discourse-cdn.com/elastic/original/3X/1/0/10b95dfd9a28977f54ef77705af47749d24aaff8.png)

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**Author:** ![Julia\_Bardi](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/julia_bardi/32/79463_2.png) [@Julia\_Bardi](https://discuss.elastic.co/u/Julia_Bardi)\
**Post date:** [August 28, 2024, 12:12pm UTC](https://discuss.elastic.co/t/error-unknown-flag-fleet-server-client-auth/364778/2 "2024-08-28T12:12:00Z")

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What is the full command you are trying? Perhaps there is an extra space there?  
The flag itself seems correct: [Elastic Agent command reference | Fleet and Elastic Agent Guide [8.15] | Elastic](https://www.elastic.co/guide/en/fleet/current/elastic-agent-cmd-options.html#elastic-agent-enroll-command)

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<div class="post-metadata">

**Author:** ![kirolosmena299](https://avatars.discourse-cdn.com/v4/letter/k/e0b2c6/32.png) [@kirolosmena299](https://discuss.elastic.co/u/kirolosmena299)\
**Post date:** [August 28, 2024, 12:37pm UTC](https://discuss.elastic.co/t/error-unknown-flag-fleet-server-client-auth/364778/3 "2024-08-28T12:37:28Z")

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many thanks, i have solved it as there was some of old logs need to be deleted.

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**Author:** ![alextg](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/alextg/32/137075_2.png) [@alextg](https://discuss.elastic.co/u/alextg)\
**Post date:** [September 10, 2024, 4:16am UTC](https://discuss.elastic.co/t/error-unknown-flag-fleet-server-client-auth/364778/4 "2024-09-10T04:16:19Z")

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I just installed the elastic client 8.14.3 in a brand new Debian server using the command below and I got the same error `unknown flag: --fleet-server-client-auth`

`sudo ./elastic-agent install --url=https://my_url:443 --enrollment-token=my_token`