Hi spacecats,
We managed to track down the issue after an exhaustive investigation.
The issue was caused by a rule in the OWASP ModSecurity ruleset in WHM/cPanel; we had to disable the following rule:
REQUEST-949-BLOCKING-EVALUATION
After disabling that rule we had no further issues with saving posts or other entries in WordPress.
Hi John,
We have tried disabling the security plugins to no avail, but we haven’t tried re-installing the ACF plugin. If we re-install the plugin, will we need to re-create all of the custom fields and data?
Any idea why the ACF fields are working with the Gutenburg editor?
