Hi Kevin,
Thanks for providing more detail, I think I know what is going on. While there is an error that gets thrown by part of Breadcrumb NavXT, the cause of the error most likely is not Breadcrumb NavXT. The filter (plugin_action_links
) being handled by the function in questions is supposed to pass in an array for the first parameter. However, some other code (likely another plugin) is messing up this first parameter so a string is passed in instead of an array. In the past, this didn’t trigger a PHP error, now it does. I recommend disabling all of the plugins other than Breadcrumb NavXT, then activate them, one-by-one until the error re-appears. Once it re-appears, you’ll know what plugin is causing the issue (and can let that plugin author know they have a bug that needs to be fixed).