acf-repeater

Have you changed any WordPress constants on this site, like WP_PLUGIN_DIR?

It looks like Wordfence (or WordPress itself) is looking for a the full path of the theme inside the plugins folder.

I cannot tell if the theme is causing the problem, since it is a premium theme and doesn’t have a free version on www.ads-software.com, unless it is listed under a different name. There may be an issue with the way the theme is bundling its plugins, but it might not show any visible errors when Wordfence isn’t active.

You could try switching themes temporarily to check if the error still happens when using another theme. (Of course, if it is a live site and it is critical to have the theme active, you may not want to try that — I also have used one theme that would reset all widgets every time it was activated, so please only try this if you know it is safe for your theme.)

I have a similar issue.

Warning: fopen(/var/www/wp-content/plugins/var/www/wp-content/themes/cs_v3/acf/acf.php): failed to open stream: No such file or directory in /var/www/wp-includes/functions.php on line 41

This comes up in Live Traffic area. Not sure where it’s getting that path from, but both acf.php & functions.php exist and the ACF plugin is working as expected.

WP_PLUGIN_DIR returns /var/www/wp-content/plugins

acf.php is located here:
/var/www/wp-content/themes/cs_v3/acf/acf.php

If other plugins or a theme cause PHP warnings while Wordfence is running, those warnings can appear at the top of the Live Traffic page. I think this is most likely the way the plugin is bundled in the themes, especially since similar messages are happening in two different themes, but on two different files in that bundled plugin.

You could check this either by enabling WP_DEBUG in your wp-config.php (though only temporarily if you don’t have a development site to test it on), or using a plugin like Query Monitor, to view the PHP warnings from the admin bar without turning on debugging.

If the error doesn’t appear with either method above, at the top of the site, it might also be that the plugin only has an error during ajax requests, which Wordfence uses to show content on a page without reloading the whole page. I think the best way to verify that would be to use WP_DEBUG, and check the log files with Wordfence enabled, and then again with it disabled, while using other plugins that use ajax.