Unable to change settings- won't save

Unable to change any settings on WordPress Cerber. I get the following message appear-


I’ve had to turn off for now as it was blocking all users.

Hi, I think this is caused by a plugin conflict. Most likely a plugin that alters or hides the WordPress dashboard URL. Could you share the list of active plugins? You can find a short version of it on the WP Cerber Diagnostic page.

Hi Garry,

Thanks for your response on this. List of plugins below:
|ACF Fields to WP REST API|1.1|
|Advanced Custom Fields PRO|6.4.0.1|
|Affinity User Activity|1.0|
|Affinity Export|1.0|
|Affinity Shared Authentication|1.0|
|Async JavaScript|2.21.08.31|
|Autoptimize|3.1.13|
|Classic Editor|1.6.7|
|Custom Post Type UI|1.17.2|
|Formidable Honeypot|0.2|
|Formidable Locations|2.03|
|Formidable Mailchimp|2.09|
|Formidable Forms Pro|6.16.4|
|Formidable Registration|3.0|
|Formidable Forms|6.20|
|WP Fast Total Search - The Power of Indexed Search|1.79.268|
|If Menu - Visibility control for menus|0.19.2|
|Post SMTP|3.1.4|
|User Status Shortcode|0.1.1|
|Yoast SEO|24.9|
|WP Cerber Security, Anti-spam, and Malware Scan|9.6.7.3|

These plugins can potentially cause conflicts: “Autoptimize”, “If Menu – Visibility control for menus”. Please try deactivating them temporarily and check if the issue with saving plugin settings persists.

Hi Garry,

Thanks for your help on this.

I disabled Autoptimize and If Menu, then activated WP Cerber and tried to update it’s settings and still got the error message.