Updating failed. The response is not a valid JSON response.
I have a site with a perfect site health score however I am receiving the above message when I try to save changes to an existing page. I have tried resaving permalinks, purging cache, closing and reopening my browser, clearing browser cache. I saw one site recommends reverting to the classic editor but I don’t want to do that. I like the block editor. Is there anything else I can do?
I would like to add this site has only 5 plugins: Akismet, Duplicator Pro, Gravity Forms, Mai Theme Engine and W3 Total Cache. All are up to date and are pretty much my standard set of plugins that I use on other sites.
I just went through plugin deactivation/reactivation but still experience the invalid JSON response problem.