# MacOS Big Sur Nginx io\_setup() failed (38: Function not implemented)
**URL:** https://community.kinsta.com/t/macos-big-sur-nginx-io-setup-failed-38-function-not-implemented/580
**Category:** Bug Reports
**Created:** [April 9, 2021, 2:49pm UTC](https://community.kinsta.com/t/macos-big-sur-nginx-io-setup-failed-38-function-not-implemented/580 "2021-04-09T14:49:41Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@nemanjac](https://community.kinsta.com/u/nemanjac)
#### Post date: [April 9, 2021, 2:49pm UTC](https://community.kinsta.com/t/macos-big-sur-nginx-io-setup-failed-38-function-not-implemented/580/1 "2021-04-09T14:49:41Z")
**Q: Date/Time this occurred (Provide your time zone also)**
**A:** April 9th 2021 GMT+2
**Q: DevKinsta Version**
**A:** 1.0.3
**Q: OS Version**
**A:** MacOS Big Sur (11.2.3 (20D91))
**Q: Docker Desktop Version**
**A:** 3.3.0
**Q: Were any error codes or messages observed? If so, what were they?**
**A:** No, the error log contains [emerg] 62#62: io\_setup() failed (38: Function not implemented)
**Q: Detailed Description of the Problem**
**A:** Nginx container becomes not responsive. Resulting in 504 after first-page opening.
Server becomes super-slow and not responsive on some pages.
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### Author:  [@michael](https://community.kinsta.com/u/michael)
#### Post date: [April 30, 2021, 4:38pm UTC](https://community.kinsta.com/t/macos-big-sur-nginx-io-setup-failed-38-function-not-implemented/580/2 "2021-04-30T16:38:38Z")
Hey @nemanjac . Thanks for reporting this. Are you still getting this issue with the latest version (v1.1.5) by chance?
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### Author:  [@nemanjac](https://community.kinsta.com/u/nemanjac)
#### Post date: [May 4, 2021, 3:36pm UTC](https://community.kinsta.com/t/macos-big-sur-nginx-io-setup-failed-38-function-not-implemented/580/3 "2021-05-04T15:36:06Z")
Sorry @michael I was away for short vacation here.
I just checked again
> 2021/05/04 15:34:18 [emerg] 63#63: io\_setup() failed (38: Function not implemented)
This line still comes in error reports.
I’m not experiencing blockages any more, which is good. But error remains.
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### Author:  [@jeff](https://community.kinsta.com/u/jeff)
#### Post date: [May 6, 2021, 4:19pm UTC](https://community.kinsta.com/t/macos-big-sur-nginx-io-setup-failed-38-function-not-implemented/580/4 "2021-05-06T16:19:06Z")
Thanks @nemanjac,
Our developers are looking into this but haven’t been able to reproduce it just yet. We’ll keep trying and we’ll update you here once we know more.
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### Author:  [@nemanjac](https://community.kinsta.com/u/nemanjac)
#### Post date: [May 7, 2021, 7:14pm UTC](https://community.kinsta.com/t/macos-big-sur-nginx-io-setup-failed-38-function-not-implemented/580/6 "2021-05-07T19:14:05Z")
Hi @jeff
Sounds good.
It is running fine now. It seems that the error is not causing any issues anymore.
It might have been something I did, as I was testing series of scripts that can customize docker fpm and nginx automatically.
Cheers,
Nemanja
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### Author:  [@michael](https://community.kinsta.com/u/michael)
#### Post date: [May 10, 2021, 5:18pm UTC](https://community.kinsta.com/t/macos-big-sur-nginx-io-setup-failed-38-function-not-implemented/580/7 "2021-05-10T17:18:41Z")
Thanks for the update! Let us know if it happens again. We’ll keep this open for a little while longer in case you find anything else here.