How to Fix a 501 Not Implemented Error on Your WordPress Site

Written on October 18, 2017. Updated on November 12, 2017

When something breaks on your WordPress site you’ll typically encounter what is called an HTTP status code. These are delivered to your browser in the HTTP header and to help you troubleshoot what might be wrong. Some status codes you’re probably familiar with include 404 “not found” errors or a 301 redirect for SEO purposes. Today we’re going to discuss a less common status code, and that is the 501 not implemented error. Follow the steps and recommendations below to resolve it.

501 Not Implemented Error

The 501 not implemented error indicates that the server does not support the functionality required to fulfill the request. This is the appropriate response when the server does not recognize the request method and is not capable of supporting it for any resource (RFC7231, section 6.6.2). A 501 response is also cacheable by default.

Due to the various browsers, web servers, and operating systems, a 501 not implemented error can present itself in a number of different ways. But they all have the same meaning. Below are just a couple of the many different variations you might see on the web:

  • “501 Not Implemented”
  • “Error 501”
  • “HTTP 501”
  • “HTTP Error 501 Not implemented”
  • “The server either does not recognize the request method, or it lacks the ability to fulfill the request.”
501 not implemented error in browser

501 not implemented error in browser

How to fix a 501 Not Implemented Error

A 501 not implemented error is almost always a problem with your web server. There are a few things you can do on your side to try and resolve it, but typically this is the type of error where you’ll need to reach out to your host to fix.

1. Try Reloading the Page

One of the easiest and first things you should try when encountering a 501 not implemented error is to simply wait a minute or so and reload the page (F5 or Ctrl + F5). It could be that the host or server will resolve the issue While you’re waiting, you could also quickly try a different browser to rule that out as an issue.

Another thing you can do is to paste the website into downforeveryoneorjustme.com. This website will tell you if the site is down or if it’s a problem on your side.

downforeveryoneorjustme
downforeveryoneorjustme

2. Clear Your Browser Cache

Whenever you encounter issues like these it can be good to clear your browser cache. Below are instructions on how to do it in the various browsers:

3. Disable Proxy Settings

This is very rare, but sometimes you might see a 501 error if you are utilizing a proxy service. Or one might have been set without you even knowing it. Follow these tutorials on how to disable or check to ensure no proxy settings are enabled:

Chrome proxy settings

Disable Chrome proxy settings

4. Reach Out To Your Host

Unlike some other HTTP status codes where there is a lot of troubleshooting you can do yourself, 501 errors are almost always an issue on the web server. They aren’t usually caused by a bad plugin or caching issue. Therefore, if it doesn’t resolve itself within a few minutes we recommend simply reaching out to your WordPress host. You can also check your WordPress host’s status page.

Typical causes of this error on the server might include:

  • There was a bad update to the server causing it to not properly respond to the browser’s request.
  • There is a misconfiguration in NGINX that needs to be fixed by an engineer.
  • The server you’re attempting to access may be overwhelmed and therefore isn’t able to properly generate the request.
  • It could also be a billing issue. If you didn’t pay your hosting bills they might default your site to 501 status before removing the account altogether. Giving you another chance to resolve the issue.

You If you are experiencing a 501 error at Kinsta simply open a support ticket and we’ll get it fixed immediately. We also proactively monitor errors like these with New Relic, so more than likely our team is already investigating.

Open support ticket

Open support ticket

If you are worried about these happening on your site in the future, you can also utilize a tool like updown.io to monitor and notify you immediately if they occur. It periodically sends an HTTP HEAD request to the URL of your choice. You can simply use your homepage. The tool allows you to set check frequencies of:

  • 15 seconds
  • 30 seconds
  • 1 minute
  • 2 minutes
  • 5 minutes
  • 10 minutes

It will send you an email if and when your site goes down. Here is an example below.

Email notification of 501 error

Email notification of 501 error

This can be especially useful if you’re on a shared host, who tend to overcrowd their servers. This can give you proof of how often your site might actually be doing down (even during the middle of the night). That’s why we always recommend going with a managed WordPress host such as Kinsta. Make sure to check out our post that explores the top 9 reasons to choose managed WordPress hosting.

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