Same problem here. I sent them a support request and recommend everyone to do that.

Hey @cyril2021 and @Jussi, thanks for reaching out about this!

I’ve separated this out into its own topic as the error differs from the original one being discussed in the previous thread. So it should be easier to keep track of this “authentication failed: 404 Not found” error here. :)

With this sort of error it appears to suggest that there is an issue with the plugin not being recognised as installed on the WordPress site we’re attempting to connect to. If the plugin is installed and activated then I’d expect this could be caused by one of the following:

• Default “Plain” permalinks are being used - e.g. https://yourwebsite.com/p=123
  Try switching WordPress to use a different permalink structure such as Post name.
• Plugin/WordPress version is incorrect
  Are the latest versions of both WordPress and the Zapier WordPress plugin being used?
• XML-RPC is disabled
  Go to Settings > Writing > Remote Publishing to check whether this is enabled.
• The WordPress site is not publicly available
  Is the website private? If so that could be what’s preventing Zapier from connecting to the website. You can make your site public by going to Settings > General > Privacy in WordPress and switching from Private to Public.

If the above suggestions don’t do the trick then I’d recommend enlisting further help from our Support team. They’ll be able to dig into the system logs for your Zaps to further investigate and are better placed to assist with troubleshooting.