Hello @margaritaperc
I’m sorry about the error you encountered. You mentioned that the error is visible in a CPT such that you can’t save the post and get another error, “Updating failed. The response is not a valid JSON response”. We usually recommend the steps below which resolves the issue:
- Install & activate the Yoast Test Helper plugin
- Go to Tools > Yoast Test
- Locate the Yoast SEO section and click on the ‘Reset indexables tables & migrations‘, ‘Reset Prominent words calculation‘, and ‘Reset Internal link counter‘ buttons. After each click, the page will reload to confirm that the specific reset was successful.
- Go to SEO > Tools, and under SEO data, click the “Start SEO data optimization” button to allow Yoast to rescan your content.
If the issue persists, we see problems occur in combination with another plugin or theme. The fastest way to rule out any conflict is to deactivate all non-Yoast plugins and switch to a standard theme like Twenty Twenty-Two.
Please test this on your development or staging site if you have one. If not, we recommend using the Health Check & Troubleshooting plugin. This plugin has a troubleshooting mode, which does not affect normal visitors to your site.
If you’re unfamiliar with checking for conflicts, we’d like to point you to a step-by-step guide that will walk you through the process: How to check for plugin conflicts
If you feel uncomfortable doing this yourself or if this does not solve your issue, our Yoast SEO Premium plugin comes with one year of (technical) support.
This thread was marked resolved due to a lack of activity, but you’re always welcome to re-open the topic. Please read this post before opening a new request.
