Thank you! We’ve got 16 active installed plugins (see below). Is there any way to know which ones are likely culprits? Turning each one one/off and testing could take quite some time.
Add Meta Tags, Advanced Custom Fields, BackUpWordPress, Black Studio TinyMCE Widget, Breadcrumb NavXT, Display widgets, Duplicate Post, Feedburner Email Widget, Google Analytics for WordPress, Image Widget, Pre Loaded, Search & Replace, Slick Social Share Buttons, Subscribe2, Subscribe2 widget, WP Social Icons